A frantic search for survivors is under way in central Texas after flash floods killed at least 32 people, including 14 children.

Many were asleep when the Guadalupe River rose more than 26 ft (8m) in less than an hour in the early hours of Friday.

Officials in Kerr County have said 27 children are missing from a Christian youth camp located along the river. Some 850 people were rescued.

Weather forecasts suggest that more rain and, potentially, more flooding could be on the horizon for the area.

Among the areas most severely hit by the floods were mobile homes, summer camps and camping sites where many had gathered for 4 July holiday celebrations.

At a press conference on Saturday afternoon, Texas Governor Greg Abbott said he had signed an expanded disaster declaration to boost search efforts.

• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

He said officials would be relentless in ensuring they locate "every single person who's been a victim of this event", adding that "we will stop when job is completed".

It remains a search and rescue mission, officials said, not a recovery effort.

They said rescuers were going up and down the Guadalupe River to try to find people who may have been swept away by the floods.

Much of the rescue has focused on a large all-girls Christian summer camp called Camp Mystic.

The camp, where 27 remain missing, is on the banks of the Guadalupe River near Hunt, Texas.

Texas Lieutenant Governor Dan Patrick told the BBC's Radio 4 PM programme that of the 27 children missing from Camp Mystic "many of these girls are younger girls under the age of 12".

He also said that many more people were likely to remain unaccounted for across the region, because some were visiting for the holiday weekend.

In an email to parents of the roughly 750 campers, Camp Mystic said that if they haven't been contacted directly, their child is considered missing.

Some of the families have already stated publicly that their children were among those who were found dead.

US President Donald Trump has said his administration is working closely with local authorities to respond to the emergency.

Homeland Security Secretary Kristi Noem said the president was "devastated" by the loss of life and promised full federal support.

Noem joined Governor Abbott at Saturday afternoon's press conference and said the federal government would soon be deploying the Coast Guard to help search efforts.

Elsewhere in central Texas, in Travis County, officials say another two people have died and 10 are missing because of the flooding.

Forecasters have warned that central Texas may see more flooding this weekend.

The National Weather Service (NWS) said the area could see 2 to 5in (5cm to 12cm) of rain on Saturday.

Up to 10in of rain was possible in some areas that are still reeling from Friday's deluge.

Two decades have passed since the 2005 London attacks, but the face of the lead suicide bomber, Mohammad Sidique Khan, has never left Dan Biddle's memory.

It feels as real today as the day they looked into each other's eyes.

"I can be in in the kitchen and he is stood in the garden," says Dan, who has complex post-traumatic stress disorder.

"He's there, dressed as he was on the day, holding the rucksack, just with his hand above it, about to detonate it again."

Even if Dan looks away, the bomber is still there when he looks back.

"I saw this guy literally disassemble himself in front of me, and now I'm seeing him again."

Warning: This article contains details some readers may find distressing

• 7 July London bombings: What happened that day?

Dan was in touching distance of Khan, on a rush-hour London Underground Circle line train on 7 July 2005. How he survived is almost beyond rational explanation.

"As as we pulled out of Edgware Road station, I could feel somebody staring at me. I was just about to turn around and say, 'What are you looking at?', and I see him put his hand in the bag.

"And then there was a just a brilliantly white, bright flash - heat like I've never experienced before."

Khan had detonated a homemade bomb - made using an al-Qaeda-devised chemical recipe - that he was carrying in his rucksack.

The device killed David Foulkes, 22, Jennifer Nicholson, 24, Laura Webb, 29, Jonathan Downey, 34, Colin Morley and Michael Brewster, both 52.

In total, 52 people were killed that day, by four bombs detonated by Islamist extremists. Another 770 were injured.

Dan was blown out of the train, hit the tunnel wall and fell into the crawl space between the tunnel wall and the track.

His injuries were catastrophic. His left leg was blown off. His right leg was severed from the knee down. He suffered second and third-degree burns to his arms, hands and face. He lost his left eye - and his hearing on that side too.

He suffered a massive laceration to his forehead. A pole from the tube train's internal fittings went into his body and he endured punctures and ruptures to his kidneys, lungs, colon and bowel. He later lost his spleen.

Dan was the most severely injured victim of the attacks to survive. And he was conscious throughout.

He initially thought the white flash was an electrical explosion.

Debris had fallen onto him, and his arms and hands were alight. He could see the flames flickering.

"Straight after the explosion, you could have heard a pin drop. It was almost as if everybody had just taken a big breath," Dan says, "and then it was like opening the gates of hell. Screaming like I've never heard before."

Dan could see some of the dead. He tried to push down to lever himself up from the debris. He realised how profusely he was bleeding.

"The initial feeling was one of total disbelief. It was like, surely God, this is just a nightmare."

Dan's mind immediately turned to his father, and how he couldn't bear for him to witness this.

"My dad cannot be the person that walks into a mortuary and goes, 'Yeah, that's my son'," Dan says. "I couldn't bear the thought of that."

He didn't believe he would get out of the tunnel. But the will to survive instinctively kicked in and he screamed for help.

The first person to respond was fellow passenger Adrian Heili, who had served as a combat medic during the Kosovo war. If it had been anyone else, Dan believes he would have died.

"The first thing he said to me was, 'Don't worry, I've been in this situation before, and never lost anyone.'

"And I'm thinking, 'How can you have gone through this before?'

"And then he said to me: 'I'm not going to lie to you. This is really going to hurt.'"

Adrian applied a tourniquet and pinched shut the artery in Dan's thigh to stop him bleeding to death. Dan's life was literally in Adrian's hands until paramedics were able to reach him about half an hour later.

Adrian helped many more in the hours that followed - and in 2009 received the Queen's Commendation for Bravery.

Dan's trauma was far from over. He was taken to nearby St Mary's Hospital where he repeatedly went into cardiac arrest. At one point, a surgeon had to manually massage his heart to bring him back to life. He was given 87 units of blood.

"I think there's something in all of us - that fundamental desire to live.

"Very few people ever get pushed to the degree where that's required.

"My survival is down to Adrian and the phenomenal care and just brilliance of the NHS and my wife."

Physical survival was one thing. But the toll on Dan's mental health was another.

After eight weeks in an induced coma, Dan began a year-long journey to leaving hospital - and he realised he'd have to navigate the world outside differently.

His nights became consumed with mental torture.

He dreaded having to close his eyes and go to sleep, because he would find himself back in the tunnel.

"I wake up and [the bomber] is standing next to me," Dan says. "I'll be driving - he's in the back seat of my car. I'll look in the shop window and there's a reflection of him - on the other side of the street."

Those flashbacks have led to what Dan describes as survivor's guilt.

"I've replayed that moment a million times over in my head. Was there something about me that made him do it? Should I have seen something about him then tried to stop it?"

By 2013 Dan had reached a dangerous low. He tried to take his own life three times.

But he had also started a relationship with his now-wife Gem - and this was a crucial turning point.

The next time he came close to suicide it was Gem's face he saw when he closed his eyes, and he realised that if he ended his own life he would inflict appalling trauma on her.

Gem persuaded Dan to take a mental health assessment - and he began to get the expert help he needed.

In 2014 he agreed - as part of his therapy and attempts to manage the condition - to do something he thought he would never do: return to Edgware Road.

When the day came, Dan sat outside the station experiencing flashbacks and hearing the sounds of 7/7 again: screams, shouting and sirens.

He and Gem pressed on. As they entered the ticket hall there were more flashbacks.

The station manager and staff were expecting him and asked if he wanted to go down to the platform. Dan said it was a "bridge too far". Gem insisted they all go together.

When they reached the platform, a train pulled in. Dan began to feel sick. But the train quietly moved on without incident - and by the time a third train had arrived he found the courage to board it.

"I feel really, really sick. I'm sweating. She's crying. I'm tensing, waiting for a blast. I'm waiting for that that big heat and that pressure to hit me."

And then the train stopped at the point in the tunnel where the bomb had gone off - an arrangement between the driver and the station manager.

"They'd stopped the train exactly where I'd been lying. I remember looking down onto the floor and it was a really weird feeling - knowing that my life really came to an end there."

As the train pulled away, something inside Dan urged him to get off at the next station and move forward with his life.

"I'm going to leave the station, I'm going to do whatever I'm going to do today, and then I'm going to marry this amazing, beautiful woman," he says. The two tied the knot the following year.

Eleven years on, Dan feels driven to do something positive with his life.

He now runs his own company helping disabled people into work - a professional journey he might never have embarked on had it not been for the bomb.

He still has flashbacks and bad days but he's finding ways to manage them - and has published a book of what he has been through.

"I'm very lucky to still be alive. I've paid an immense, enormous price. I'll just keep fighting every day to make sure that him and his actions never win."

A list of organisations in the UK offering support and information with some of the issues in this story is available at BBC Action Line

When the BBC revealed that MI5 had lied to three courts, the Security Service apologised for giving false evidence - vowing to investigate and explain how such a serious failure had occurred.

But on Wednesday, the High Court ruled that these inquiries were "deficient", ordering a new "robust" investigation. A panel of judges said they would consider the issue of contempt of court proceedings against individuals once that was complete.

Now we can detail how, over the past few months leading up to the judgment, MI5 continued to provide misleading evidence and tried to keep damning material secret.

The material gives an unprecedented insight into the internal chaos at MI5 as it responded to what has become a major crisis and test of its credibility.

At the heart of the case is the violent abuse of a woman by a state agent under MI5's control. After the BBC began investigating, MI5 attempted to cover its tracks - scattering a trail of false and misleading evidence.

The case started very simply: I was investigating a neo-Nazi, who I came to understand was also an abusive misogynist and MI5 agent.

After I contacted this man - known publicly as X - in 2020 to challenge him on his extremism, a senior MI5 officer called me up and tried to stop me running a story.

The officer said X had been working for MI5 and informing on extremists, and so it was wrong for me to say he was an extremist himself.

It was this disclosure, repeated in a series of phone calls, which the Security Service would later lie about to three courts as it attempted to keep X's role and identity shrouded in secrecy.

During the phone calls with me, MI5 denied information I had about X's violence, but I decided to spend more time investigating. What I learned was that X was a violent misogynist abuser with paedophilic tendencies who had used his MI5 role as a tool of coercion.

He had attacked his girlfriend - known publicly as "Beth" - with a machete, and abused an earlier partner, whose child he had threatened to kill. He even had cannibal fantasies about eating children.

When I challenged both X and MI5 with our evidence, the government took me and the BBC to court in early 2022. They failed to stop the story but did win legal anonymity for X.

Arguing for secrecy in a succession of court proceedings, the Security Service told judges it had stuck to its core policy of neither confirming nor denying (NCND) informants' identities, including during conversations with me. Crucially, this stance allowed it to keep evidence secret from "Beth", who had taken MI5 to court.

The service aggressively maintained its position until I produced evidence proving it was untrue - including a recording of one of the calls with a senior MI5 officer.

Finally accepting it had provided false evidence, MI5's director general Sir Ken McCallum said: "We take our duty to provide truthful, accurate and complete information very seriously, and have offered an unreserved apology to the court."

Two investigations were commissioned: an internal MI5 disciplinary inquiry, and an external review by Sir Jonathan Jones KC, who was once the government's chief lawyer. This latter review was personally commissioned by the Home Secretary Yvette Cooper and MI5's director general.

Both of these concluded that the original false evidence was not due to dishonesty by MI5 or any of its officers. They effectively put it down to mistakes, both personal and systemic.

But these two inquiries quickly began to fall apart.

Not fair or accurate

The government initially refused to provide both reports in full to the court.

Like many cases involving MI5, this one was held partly in secret to allow the government to use evidence which it says is too sensitive to be discussed in open hearings.

Access to the secret, closed part of the case was only available to the government, the judge and security-cleared barristers known as special advocates who were representing the BBC - but who were not allowed to communicate directly with us.

The government said it would not be providing any closed evidence about the two inquiries to the judge or the special advocates.

Instead, it provided an "open" version of Sir Jonathan's external review, with apparently sensitive material edited out, and it purported to provide a full account of the internal inquiry in a witness statement by MI5's director general of strategy - known as Witness B.

Sir Jonathan wrote that he was "satisfied" that the open version was a "fair and accurate" account of his full review. Witness B, third-in-command at the Security Service, said in his statement: "I am satisfied that there is nothing in the closed material that has been excluded from the open report which prevents MI5 from providing the court with a frank and accurate account."

During hearings, the government argued against disclosing secret material to the court. It eventually agreed to hand over the secret version of Sir Jonathan's review, and then was ordered to disclose the internal investigation report described by Witness B, along with policy documents and notes of interviews with MI5 officers.

When the disclosure came, it was clear why MI5 was so keen to keep it secret: the summaries, including the one from MI5's third-in-command, were not fair or accurate. Key information had been withheld, which undermined their conclusions.

In short, the court was still being misled.

At the same time, in response to the inquiries, I was submitting new evidence which proved that some of the claims made by the two reviews were false.

Neither the internal investigation nor Sir Jonathan Jones contacted me, despite the fact I was the only other person who really knew what had been said in all the phone calls at the centre of the case.

'The fallibility of memory'

The two official reviews concluded that the senior officer who called me - Officer 2 - failed to recall telling me that X was an agent.

"There is nothing surprising in this narrative, which is ultimately about the fallibility of memory in the absence of a written record," as the Security Service put it in legal submissions.

The Jones review said that, because no formal record was made of the calls, by the time MI5 was preparing evidence the "only first-hand evidence available was Officer 2's personal recollection".

Sir Jonathan said the officer's recollection was "uncertain", although it had hardened over time into a position that he had not departed from NCND.

But material that MI5 and the government sought to keep secret shows that Officer 2 gave a detailed recollection of the conversation with me - until I exposed it as false.

His recollection was contained in a note of an internal MI5 meeting, arranged to discuss what to tell the special advocates and the court about the conversations with me. In it, the officer insisted he did not depart from NCND and gave a melodramatic account of my "long pauses" as I said I needed the story, before I eventually became cooperative and said I had "seen the light".

This was all untrue. He also falsely claimed I had revealed that I had spoken to X's former girlfriend, when I had done no such thing.

The note also showed that Officer 2 had told colleagues that he persuaded me to drop the story by implying that agent X was being investigated by MI5 as an extremist. This was the exact opposite of what he had in fact told me, which was that X was an MI5 agent rather than a real extremist.

Sir Jonathan was aware of the full version of this elaborate false account, but it was absent from the unclassified version given to the court and the BBC.

The MI5 internal review also claimed that Officer 2 had a lapse of memory.

It said that Officer 2 had told another officer - a key figure involved in preparing the Security Service's false evidence for the court, known as Officer 3 - that he could not remember whether he had departed from NCND.

In his statement to court, Witness B - MI5's director general of strategy - said Officer 2 had said "they could not recall the details" of the conversations with me but "did not think they had departed from NCND" and believed "they would have remembered if they had done so".

But an internal note by Officer 3, written after his discussion with Officer 2, contained a very different account.

It stated unequivocally that "we did not breach NCND" and that the contact with me "was prefaced with confirmation that this conversation was not on the record".

It also stated that, "after being initially fairly bullish, De Simone said that he acknowledged the strength of the argument, and agreed to remove those references".

All three claims were false, including about the conversations being off the record, something now accepted by MI5.

The evidence showed specific false claims being presented as memories - not the absence of memory the two inquiries said they found.

The written records MI5 said did not exist

The question of memory was so important because the court was told that written records were not available.

Witness B - MI5's third-in-command - said the internal investigation established that Officer 2 had "updated colleagues within MI5" about the conversations with me, but that "there was no evidence identified of any written record being made, by Officer 2 or anyone else".

"The fact of the matter was that Officer 2 was reliant on personal recollection alone which inevitably carries a degree of inherent uncertainty," Witness B said in his statement to court.

Sir Jonathan gave the same impression in his review.

But the secret material MI5 was forced to hand over proved this was false. There were several written records consistent with what had really happened - that MI5 had chosen to depart from NCND and that several people were aware of it.

There was a decision log.

There were notes of conversations with Agent X himself.

There were emails.

The decision log showed that, just after the authorisation took place, a formal record was created saying the plan was to call the BBC and "reveal the MI5 link to X". The log then noted: "This was discussed with Officer 2 who subsequently approached the BBC to begin this conversation."

In an internal email, after I had said I would not include X in an initial story, one of X's handling team reported this development to other MI5 officers and accurately described the approach to me, namely that Officer 2 had claimed my proposed story was "incorrect" and the rationale for this was that most of the material was as a "direct result of his tasking" as an MI5 agent.

Notes of calls and meeting with Agent X show he approved the plan to reveal his MI5 role and was kept updated about the calls. In a later meeting with him, MI5 recorded that he was "happy" to meet with me, which was an offer MI5 had made and I ignored.

But it showed that MI5 and X were well aware of the NCND departure, because the Security Service would obviously only try to arrange a meeting with someone like X if they were an agent.

In a telling note, MI5 said X thought that a meeting with me would "hopefully serve to counter some of the conclusions that the journalist had reached about X". This is a violent, misogynistic neo-Nazi, a danger to women and children, yet MI5 wanted to do PR for him with a journalist.

'Back in the box'

These records and others show that the handling team for agent X understood there had been an NCND departure. This was unsurprising as the calls with me at the time made it clear that his case officers knew what was happening.

But the internal investigation report records how, as MI5 was preparing to take the BBC to court to block our story on X, one officer went around convincing colleagues that no such departure had ever taken place.

Officer 3 spoke several times to a member of the agent-handling team within MI5 - known as Officer 4 - regarding what had been said to me about X.

"We have already named him pal," said Officer 4, according to Officer 4's evidence to the investigation and Officer 3 replied: "I can categorically tell you we didn't".

After these conversations, Officer 4 said he felt the other officer had put him "back in his box". Other members of the handling team thought what Officer 3 was saying was "odd" and "weird".

MI5 has given completely contradictory explanations for how the false claim about not departing from NCND had got into its witness statement.

The claim was given to court by an officer known as Witness A, acting as a corporate witness - meaning he was representing the organisation rather than appearing as someone necessarily involved personally in the events.

When the government was trying to stop the BBC publishing its story about X in 2022, the BBC's special advocates asked how Witness A could be so sure that NCND had not been breached.

The government's lawyers said "Witness A spoke to the MI5 officer who had contact with the BBC" - meaning Officer 2 - and the officer had said he neither confirmed nor denied agent X's role. The lawyers' answers strongly appeared to suggest that the pair had even spoken at the time of the calls with me.

After we exposed Witness A's false evidence, the lawyers' answers created a problem for MI5 as it either suggested Officer 2 had lied all along - or that he and Witness A were both lying.

It has since been claimed that the men did not speak to each other at the time of the calls with me.

Despite not reconciling these contradictory accounts, the investigation concluded "the parties were collectively doing their best to prepare a witness statement that was accurate".

Five times MI5 abandoned 'neither confirm nor deny'

Officer 2 claimed that he had never departed from NCND before and said that was a key reason why he would have recalled doing so.

But new evidence I submitted to court showed he had also told me whether or not five other people I was investigating were working with the Security Service. One of them was an undercover MI5 officer - one of the most sensitive and memorable details an officer could disclose.

Officer 2 had invited me to meet this undercover officer, just as he had offered me the chance to meet Agent X. I had not pursued either offer, which I thought were a crude attempt at pulling me into MI5's orbit.

Indeed, the internal MI5 material suggests that its officers wrongly believe that the role of journalists is to be cheerleaders for the Security Service. I was variously described as "bullish", "stubborn", "awkward", and not "as on board as other journalists".

They said, before their involvement with me, the BBC was seen as "friendly" and "supportive" of MI5. In reality, journalists like me are here to scrutinise and challenge the organisation.

The five other NCND departures were not apparently uncovered by MI5's internal investigators, nor by Sir Jonathan Jones.

Disclosing agent X's role would have been memorable and unusual on its own.

But the fact there were also departures on NCND relating to five other people made the chain of events even more extraordinary, and made any claimed loss of memory by Officer 2 – and in MI5 more widely – simply unbelievable.

The missing interviews

Both inquiries failed to speak to key people who were on the calls they were supposed to be investigating. Neither of them spoke to me - but there were other omissions too.

Sir Jonathan's review wrongly claimed that "only Officer 2 had been party to the calls" with me. In fact, Officer 2 had invited another senior officer to join one of the calls. He introduced himself by saying: "I head up all counter-terrorism investigations here."

He referred to my earlier "conversations" with Officer 2 and was plainly aware of their content - he even made a specific pun about something connected to X.

While MI5's internal investigation was aware that the head of counter-terror investigations had joined one of the calls and mentioned it in their secret report, investigators never bothered interviewing him.

After I submitted new evidence, MI5 was forced to speak to him - but the internal investigators concluded there was nothing to show he knew about NCND departures.

Sir Jonathan had also failed to speak to the MI5 officer at the centre of the case, Officer 2. He had simply adopted the conclusions of the internal inquiry - in which MI5 was investigating itself.

It emerged during the court case that Sir Jonathan did speak to MI5 director general Sir Ken McCallum for his investigation. But when the BBC's special advocates requested any notes of the interview, they were told that none existed.

'Maintaining trust'

"MI5's job is to keep the country safe," Sir Ken said after the High Court judgement. "Maintaining the trust of the courts is essential to that mission."

Because of this case, the courts have made plain that MI5's practices should change. The government says it is reviewing how the service prepares and gives evidence.

Because NCND has been abandoned in relation to Agent X, Beth will now have a fairer trial of her legal claim against MI5. The monolithically consistent way in which the policy has been presented, including in a string of important cases, has been shown to be untrue.

This has become a story about whether MI5 can be believed, and about how it uses its privileged position to conceal and lie.

But in the beginning - and in the end - it is a story about violence against women and girls, about the importance placed on that crucial issue by the state, and about how covering up for abusive misogynists never ends well.

Asked last month whether he was planning to join Israel in attacking Iran, US President Donald Trump said "I may do it. I may not do it. Nobody knows what I'm going to do".

He let the world believe he had agreed a two-week pause to allow Iran to resume negotiations. And then he bombed anyway.

A pattern is emerging: The most predictable thing about Trump is his unpredictability. He changes his mind. He contradicts himself. He is inconsistent.

"[Trump] has put together a highly centralised policy-making operation, arguably the most centralised, at least in the area of foreign policy, since Richard Nixon," says Peter Trubowitz, professor of international relations at the London School of Economics.

"And that makes policy decisions more dependent on Trump's character, his preferences, his temperament."

Trump has put this to political use; he has made his own unpredictability a key strategic and political asset. He has elevated unpredictability to the status of a doctrine. And now the personality trait he brought to the White House is driving foreign and security policy.

It is changing the shape of the world.

Political scientists call this the Madman Theory, in which a world leader seeks to persuade his adversary that he is temperamentally capable of anything, to extract concessions. Used successfully it can be a form of coercion and Trump believes it is paying dividends, getting the US's allies where he wants them.

But is it an approach that can work against enemies? And could its flaw be that rather than being a sleight of hand designed to fool adversaries, it is in fact based on well established and clearly documented character traits, with the effect that his behaviour becomes easier to predict?

Attacks, insults and embraces

Trump began his second presidency by embracing Russian President Vladimir Putin and attacking America's allies. He insulted Canada by saying it should become the 51st state of the US.

He said he was prepared to consider using military force to annex Greenland, an autonomous territory of America's ally Denmark. And he said the US should retake ownership and control of the Panama Canal.

Article 5 of the Nato charter commits each member to come to the defence of all others. Trump threw America's commitment to that into doubt. "I think Article 5 is on life support" declared Ben Wallace, Britain's former defence secretary.

Conservative Attorney General Dominic Grieve said: "For now the trans-Atlantic alliance is over."

A series of leaked text messages revealed the culture of contempt in Trump's White House for European allies. "I fully share your loathing of European freeloaders," US Defence Secretary Pete Hegseth told his colleagues, adding "PATHETIC".

In Munich earlier this year, Trump's Vice-President JD Vance said the US would no longer be the guarantor of European security.

That appeared to turn the page on 80 years of trans-Atlantic solidarity. "What Trump has done is raise serious doubts and questions about the credibility of America's international commitments," says Prof Trubowitz.

"Whatever understanding those countries [in Europe] have with the United States, on security, on economic or other matters, they're now subject to negotiation at a moment's notice.

"My sense is that most people in Trump's orbit think that unpredictability is a good thing, because it allows Donald Trump to leverage America's clout for maximum gain…

"This is one of of his takeaways from negotiating in the world of real estate."

Trump's approach paid dividends. Only four months ago, Sir Keir Starmer told the House of Commons that Britain would increase defence and security spending from 2.3% of GDP to 2.5%.

Last month, at a Nato summit, that had increased to 5%, a huge increase, now matched by every other member of the Alliance.

The predictability of unpredictability

Trump is not the first American president to deploy an Unpredictability Doctrine. In 1968, when US President Richard Nixon was trying to end the war in Vietnam, he found the North Vietnamese enemy intractable.

"At one point Nixon said to his National Security Advisor Henry Kissinger, 'you ought to tell the North Vietnamese negotiators that Nixon's crazy and you don't know what he's going to do, so you better come to an agreement before things get really crazy'," says Michael Desch, professor of international relations at Notre Dame University. "That's the madman theory."

Julie Norman, professor of politics at University College London, agrees that there is now an Unpredictability Doctrine.

"It's very hard to know what's coming from day to day," she argues. "And that has always been Trump's approach."

Trump successfully harnessed his reputation for volatility to change the trans-Atlantic defence relationship. And apparently to keep Trump on side, some European leaders have flattered and fawned.

Last month's Nato summit in The Hague was an exercise in obsequious courtship. Nato Secretary General Mark Rutte had earlier sent President Trump (or "Dear Donald") a text message, which Trump leaked.

"Congratulations and thank you for your decisive action in Iran, it was truly extraordinary," he wrote.

On the forthcoming announcement that all Nato members had agreed to increase defence spending to 5% of GDP, he continued: "You will achieve something NO president in decades could get done."

Anthony Scaramucci, who previously served as Trump's communications director in his first term, said: "Mr Rutte, he's trying to embarrass you, sir. He's literally sitting on Air Force One laughing at you."

And this may prove to be the weakness at the heart of Trump's Unpredictability Doctrine: their actions may be based on the idea that Trump craves adulation. Or that he seeks short-term wins, favouring them over long and complicated processes.

If that is the case and their assumption is correct, then it limits Trump's ability to perform sleights of hand to fool adversaries - rather, he has well established and clearly documented character traits that they have become aware of.

The adversaries impervious to charm and threats

Then there is the question of whether an Unpredictability Doctrine or the Madman Theory can work on adversaries.

Ukrainian President Volodymyr Zelensky, an ally who was given a dressing down by Trump and Vance in the Oval Office, later agreed to grant the US lucrative rights to exploit Ukrainian mineral resources.

Vladimir Putin, on the other hand, apparently remains impervious to Trump's charms and threats alike. On Thursday, following a telephone call, Trump said he was "disappointed" that Putin was not ready to end the war against Ukraine.

And Iran? Trump promised his base that he would end American involvement in Middle Eastern "forever wars". His decision to strike Iran's nuclear facilities was perhaps the most unpredictable policy choice of his second term so far. The question is whether it will have the desired effect.

The former British Foreign Secretary, William Hague, has argued that it will do precisely the opposite: it will make Iran more, not less likely, to seek to acquire nuclear weapons.

Prof Desch agrees. "I think it's now highly likely that Iran will make the decision to pursue a nuclear weapon," he says. "So I wouldn't be surprised if they lie low and do everything they can to complete the full fuel cycle and conduct a [nuclear] test.

"I think the lesson of Saddam Hussein and Muammar Gaddafi is not lost on other dictators facing the US and potential regime change...

"So the Iranians will desperately feel the need for the ultimate deterrent and they'll look at Saddam and Gaddafi as the negative examples and Kim Jong Un of North Korea as the positive example."

One of the likely scenarios is the consolidation of the Islamic Republic, according to Mohsen Milani, a professor of politics at the University of South Florida and author of Iran's Rise and Rivalry with the US in the Middle East.

"In 1980, when Saddam Hussein attacked Iran his aim was the collapse of the Islamic Republic," he says. "The exact opposite happened.

"That was the Israeli and American calculation too... That if we get rid of the top guys, Iran is going to surrender quickly or the whole system is going to collapse."

A loss of trust in negotiations?

Looking ahead, unpredictability may not work on foes, but it is unclear whether the recent shifts it has yielded among allies can be sustained.

Whilst possible, this is a process built largely on impulse. And there may be a worry that the US could be seen as an unreliable broker.

"People won't want to do business with the US if they don't trust the US in negotiations, if they're not sure the US will stand by them in defence and security issues," argues Prof Norman. "So the isolation that many in the MAGA world seek is, I think, going to backfire."

German Chancellor Friedrich Merz for one has said Europe now needs to become operationally independent of the US.

"The importance of the chancellor's comment is that it's a recognition that US strategic priorities are changing," says Prof Trubowitz. "They're not going to snap back to the way they were before Trump took office.

"So yes, Europe is going to have to get more operationally independent."

This would require European nations to develop a much bigger European defence industry, to acquire kit and capabilities that currently only the US has, argues Prof Desch. For example, the Europeans have some sophisticated global intelligence capability, he says, but a lot of it is provided by the US.

"Europe, if it had to go it alone, would also require a significant increase in its independent armaments production capability," he continues. "Manpower would also be an issue. Western Europe would have to look to Poland to see the level of manpower they would need."

All of which will take years to build up.

So, have the Europeans really been spooked by Trump's unpredictability, into making the most dramatic change to the security architecture of the western world since the end of the Cold War?

"It has contributed," says Prof Trubowitz. "But more fundamentally, Trump has uncorked something… Politics in the United States has changed. Priorities have changed. To the MAGA coalition, China is a bigger problem than Russia. That's maybe not true for the Europeans."

And according to Prof Milani, Trump is trying to consolidate American power in the global order.

"It's very unlikely that he's going to change the order that was established after World War Two. He wants to consolidate America's position in that order because China is challenging America's position in that order."

But this all means that the defence and security imperatives faced by the US and Europe are diverging.

The European allies may be satisfied that through flattery and real policy shifts, they have kept Trump broadly onside; he did, after all, reaffirm his commitment to Article 5 at the most recent Nato summit. But the unpredictability means this cannot be guaranteed - and they have seemed to accept that they can no longer complacently rely on the US to honour its historic commitment to their defence.

And in that sense, even if the unpredictability doctrine comes from a combination of conscious choice and Trump's very real character traits, it is working, on some at least.

Top image credit: Getty Images

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Stone stacks are a common sight along hiking trails up and down the UK.

But one walker is on a mission to highlight the damage they can do to the environment - by kicking them over.

Stuart Cox says some people have been building the stacks - some as tall as 6ft (1.8m) - using stones taken from an old wall near Mam Tor in the Peak District in Derbyshire.

A recent video he filmed of himself kicking down the stacks has been watched more than a million times on social media.

And the Peak District National Park Authority says the structures are "detrimental" to the area, and have become more prevalent in recent years.

"Look at this," Stuart says, before swearing in frustration during his Facebook video on 20 May.

"Destroy the lot of them." He then proceeds to kick down a stone stack.

The 57-year-old, who works as a chartered engineer, lives in the Derbyshire village of Castleton, a short drive from Mam Tor.

He's passionate about the area, and regularly documents his hikes on his Peak District Viking page.

But his post about the dozens of stacks, built next to the busy Great Ridge footpath - about a 15-minute hike from the summit of Mam Tor - has received the most engagement.

"The majority of people have been quite supportive saying: 'Yeah, I hate them. We reduce them back to their natural state if we see them. Totally agree with you'," he said.

"Then I had the opposite reaction which was: 'Don't tell me what to do. I'll build them if I want and I'll carry on regardless'.

"I even had a couple of threats by private message, but I don't worry about those."

The Peak District is far from the only location where stone stacks have proven problematic. For example, campaigners said towers of stones on a Scottish beach were a worrying trend.

Stuart says the stacks in his video have been built using stones taken from a former boundary wall, which ran alongside the popular Great Ridge walk.

He is concerned this has damaged the habitats of the small creatures - such as frogs, toads and insects - that lived inside the wall.

It is a view shared by the National Trust.

"The majority of the stone stacks featured in this video are not on National Trust land," a spokesperson said.

"However, there have been stacks created on parts of Mam Tor, and staff and volunteers will infrequently disassemble any found."

The trust says stone stacks have also been an issue on land it is responsible for.

It added rangers had carried out extensive work to protect and preserve the hillfort at Mam Tor, which is a "scheduled monument and is of great archaeological importance".

"The Peak Forest Wall is also historically significant, itself dating back to 1579," a spokesperson added.

"Sadly, the stone stacks are not only impacting the history of the site, but they are also affecting the natural habitats of wildlife that live and feed within these ancient walls.

"In the longer-term, it will disrupt the delicate balance of the landscape."

Stuart says there is evidence of stones being removed from paths, which he says could lead to further erosion at an already popular walking spot.

According to The Countryside Code, visitors should "leave rocks, stone, plants and trees as you find them and take care not to disturb wildlife including birds that nest on the ground".

Anna Badcock, cultural heritage manager at the national park authority, says the stacks damage the "special qualities" of the national park and that the problem has got worse in recent years.

"[Stone stacks] are created by stone removed from historic features," she said.

"They are very detrimental to the historic environment which we have a statutory duty to conserve.

"Like walkers' cairns [a marker along a trail], once one is created, it encourages more."

The authority says its rangers generally do not remove the stacks "unless they are dangerous or causing an obstruction on a right of way".

"We're aware that the National Trust rangers have removed some at Mam Tor for this very reason," a spokesperson added.

Stuart said he had tried to make contact with the owner of the land on which the stacks are located, and had offered to help rebuild the wall.

And while his video has attracted some debate on social media, he hopes it might make a small difference to the place he loves.

He added: "I'm very passionate about the area, it's an area people live and work in, and to see it being trashed, you know, it does rile you a bit.

"The more important element [of reaction to his video] was: 'I thought you were a bit of a fool when I first watched the start of the video but by the time I got to the end of it I realised, actually I didn't know that and from now on I will not build the stacks'.

"That's the important bit for me. Even if a handful of people have realised the error of their ways, then that made it all the more worthwhile."

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Sabrina Carpenter brought her signature sugary pop sound to a crowd of 65,000 at London's BST Festival on Saturday night.

The 26-year-old has built a brand around sexual confidence and racy lyrics, which were noticeably toned down as the US singer embraced a more family friendly show in London's Hyde Park.

At one point a graphic flashed up on screen advising "parental discretion" as Carpenter launched into album track Bed Chem. She ditched her usual sexually suggestive performance on song Juno and instead used a cannon to fire t-shirts into the crowd.

Despite these changes she was still at her best, storming through a 17-song tracklist that comprised her biggest hits, charming the crowd with her Hollywood smile and incredibly bouncy hair.

Carpenter writes music for women of the dating app generation and her songs are filled with the type of anecdotes you've heard over Friday night drinks with the girls - from the anger over not getting closure to the fear of a man embarrassing you when they meet all your friends.

Perhaps that is what makes her so relatable. She's a talented singer and dancer who shot to fame on the Disney Channel, but she could also so easily be your mate who brings over ice cream when you're going through a break-up.

Her ability to switch from a sassy upbeat dance number to a vulnerable, acoustic solo performance is also impressive.

She's an accomplished performer for someone whose breakout hit, Espresso, is little over a year old. But much to the surprise of many, she's been in this game for a very long time.

The Pennsylvania-born star began posting videos of herself on YouTube at the age of 10 and came third in a competition to find the next Miley Cyrus a year later.

After starring in a few small acting roles, the singer became a bona fide Disney star in 2013 when she was cast in TV series Girl Meets World.

She began releasing music the following year and has released six albums to date, but has only recently received global recognition.

Carpenter became the first female artist to hold both the number one and number two positions on the UK singles chart for three consecutive weeks in 2024 and she also became the first artist in 71 years to spend 20 weeks at the top of the charts with Espresso.

From watching her live, it appears she's been waiting patiently for this moment for quite some time, to perform on the biggest stages around the world and to thousands of fans - something she references a few times between songs.

She told the crowd she was "so, so grateful" that the audience had chosen to spend their Saturday evening with her, gushing that "London is so fun and there's so much to do here".

Much of the cheekiness she has built her brand on was weaved in throughout her performance, including 1950s style infomercials advertising sprays that erase no-good men from your life and mattresses that are perfect for "activities".

But aside from a racy rendition of Bed Chem and a snippet of Pony by Ginuine (one for the Magic Mike fans) the show was more PG than expected.

Perhaps it was due to the large volume of young children stood in the crowd amongst us Gen Zs and millennials.

Or perhaps the pop princess needs a break from making headlines.

The first was back in March, when her Brit Awards opening performance was criticised for being too racy for pre-watershed television.

Media watchdog Ofcom received more than 800 complaints, with the majority relating to Carpenter's choreography with dancers dressed in Beefeater outfits.

Then in June this year she was once again under fire for sharing artwork for her new album, Man's Best Friend, which showed her on her hands and knees in a short dress whilst an anonymous man in a suit grabbed her hair.

Carpenter then revealed alternative artwork she said was "approved by God" and shows her holding the arm of a suited man.

Criticism for the original artwork came from charities including Glasgow Women's Aid which supports victims of domestic abuse. It said Carpenter's album cover was "regressive" and "promotes an element of violence and control".

Heather Binning of Women's Rights Network, also told the BBC that violence against women should "never be used as satire".

But what Saturday's performance showed is that Carpenter is a true professional, someone who can easily adapt both her style and setlist to cater to different audiences.

She ended the show perfectly, taking to a crane that panned across the huge mass of people, thrilling fans and giving them the opportunity for a close-up video to post on their social media.

"Damn nobody showed up," she joked, adding: "London thank you so much for having us tonight, this has to be one of the biggest shows I've played in my entire life."

She wrapped up with Espresso, marking the end of the show by downing some in martini-form from a crystal glass.

There were a few mutters from the crowd, who perhaps were expecting a special guest or two, but it was clear from the offset that this would be a defining moment in the popstar's career and one where she only wants the spotlight on her.

A frantic search for survivors is under way in central Texas after flash floods killed at least 32 people, including 14 children.

Many were asleep when the Guadalupe River rose more than 26 ft (8m) in less than an hour in the early hours of Friday.

Officials in Kerr County have said 27 children are missing from a Christian youth camp located along the river. Some 850 people were rescued.

Weather forecasts suggest that more rain and, potentially, more flooding could be on the horizon for the area.

Among the areas most severely hit by the floods were mobile homes, summer camps and camping sites where many had gathered for 4 July holiday celebrations.

At a press conference on Saturday afternoon, Texas Governor Greg Abbott said he had signed an expanded disaster declaration to boost search efforts.

• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

He said officials would be relentless in ensuring they locate "every single person who's been a victim of this event", adding that "we will stop when job is completed".

It remains a search and rescue mission, officials said, not a recovery effort.

They said rescuers were going up and down the Guadalupe River to try to find people who may have been swept away by the floods.

Much of the rescue has focused on a large all-girls Christian summer camp called Camp Mystic.

The camp, where 27 remain missing, is on the banks of the Guadalupe River near Hunt, Texas.

Texas Lieutenant Governor Dan Patrick told the BBC's Radio 4 PM programme that of the 27 children missing from Camp Mystic "many of these girls are younger girls under the age of 12".

He also said that many more people were likely to remain unaccounted for across the region, because some were visiting for the holiday weekend.

In an email to parents of the roughly 750 campers, Camp Mystic said that if they haven't been contacted directly, their child is considered missing.

Some of the families have already stated publicly that their children were among those who were found dead.

US President Donald Trump has said his administration is working closely with local authorities to respond to the emergency.

Homeland Security Secretary Kristi Noem said the president was "devastated" by the loss of life and promised full federal support.

Noem joined Governor Abbott at Saturday afternoon's press conference and said the federal government would soon be deploying the Coast Guard to help search efforts.

Elsewhere in central Texas, in Travis County, officials say another two people have died and 10 are missing because of the flooding.

Forecasters have warned that central Texas may see more flooding this weekend.

The National Weather Service (NWS) said the area could see 2 to 5in (5cm to 12cm) of rain on Saturday.

Up to 10in of rain was possible in some areas that are still reeling from Friday's deluge.

An eight-year-old girl and the director of an all-girls' summer camp are among the victims of flash floods in Texas that have claimed at least 43 lives, including 15 children.

Officials say most of the victims have been identified, though the identities of six adults and a child remain unknown. Authorities have not yet released any names publicly.

Here's what we know so far about the victims.

Renee Smajstrla

Eight-year-old Renee Smajstrla was at Camp Mystic when flooding swept through the summer camp for girls, her uncle said in a Facebook post.

"Renee has been found and while not the outcome we prayed for, the social media outreach likely assisted the first responders in helping to identify her so quickly," wrote Shawn Salta, of Maryland.

"We are thankful she was with her friends and having the time of her life, as evidenced by this picture from yesterday," he wrote. "She will forever be living her best life at Camp Mystic."

Camp Mystic, where 27 children are missing, is a nearly century-old Christian summer camp for girls on the banks of the Guadalupe River near Hunt, Texas.

Operated by generations of the same family since the 1930s, the camp's website bills itself as a place for girls to grow "spiritually" in a "wholesome" Christian atmosphere "to develop outstanding personal qualities and self-esteem".

Jane Ragsdale

Heart O' the Hills is another all-girls' camp that sits along the Guadalupe River, and it was right in the path of Friday's flood.

Jane Ragsdale, described as the "heart and soul" of Heart O'Hills, "did not make it", a post shared on the camp's official website said on Saturday.

Ragsdale, who started off as a camper then a counsellor, became the director and co-owner of the camp in 1976.

"We are mourning the loss of a woman who influenced countless lives and was the definition of strong and powerful," the camp website post said.

Heart O' the Hills wasn't in session and "most of those who were on camp at the time have been accounted for and are on high ground", the statement said.

"Access to the site is difficult, and authorities are primarily focused on locating the missing and preventing further loss of life and property".

Sarah Marsh

Sarah Marsh, a student at Cherokee Bend Elementary School in Texas, would have entered third grade in August.

She, too, was attending Camp Mystic when the floods struck, and reported as missing along with about two dozen other campers.

Her grandmother, Debbie Ford Marsh, took to Facebook on Friday asking for prayers. Just hours later she shared online that her granddaughter was among the girls killed.

"We will always feel blessed to have had this beautiful spunky ray of light in our lives. She will live on in our hearts forever!" Ms Ford Marsh wrote on Facebook.

In a post on Facebook, Alabama Senator Katie Britt said she's "heartbroken over the loss of Sarah Marsh, and we are keeping her family in our thoughts and prayers during this unimaginable time".

Lila Bonner

Nine-year-old Lila Bonner, a Dallas native was found dead after flooding near Camp Mystic, according to NBC News.

"In the midst of our unimaginable grief, we ask for privacy and are unable to confirm any details at this time," her family said in a statement to the news outlet.

"We ache with all who loved her and are praying endlessly."

The warning signs were already flashing as hundreds of young people celebrated the Fourth of July public holiday at Camp Mystic, an all-girls' Christian summer retreat, nestled on the banks of the Guadalupe River in Texas.

There had not been a drop of rain in the area recently until the inundation, when the river rose 26ft (8m) in less than an hour, according to state officials.

By Saturday afternoon, at least 43 people were dead, including 15 children.

• Frantic search for survivors
• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

The first hint of the devastation to come appeared on Thursday morning as rain and thunderstorms soaked a number of central Texas counties.

The National Weather Service (NWS) issued a common warning called a flood watch at 13:18 that afternoon for parts of the region, including Kerr County.

In the early hours of Friday, the outlook became more dire as the NWS issued a series of upgraded warnings. The San Saba river, the Concho River and the Colorado River were rising.

At 04.03, the NWS sent a "particularly dangerous situation" alert, reserved for the most urgent and potentially deadly scenarios such as wildfires.

Another "particularly dangerous situation" warning was issued for the city of Kerrville at 05.34, before dawn on Friday.

"Residents and campers should SEEK HIGHER GROUND NOW! Life threatening flash flooding along the river is expected," forecasters said.

"Automated rain gauges indicate a large and deadly flood wave is moving down the Guadalupe River. Flash flooding is already occurring."

Such alerts are shared on NWS social media accounts and by broadcast news outlets, but most people were asleep.

Elinor Lester, 13, said younger campers at Camp Mystic were bunked in cabins closer to the riverbank and those were the first to flood.

"The camp was completely destroyed," Elinor, who was evacuated by helicopter, told the Associated Press news agency. "It was really scary."

Just outside Kerrville, the BBC met Jonathan and Brittany Rojas as they came to see what was left of a relative's home. Only the foundations remain.

Five people were in the house the night of the deluge - the mother and her baby are still missing.

The teenage son, Leo, survived after he became snared in barbed wire, preventing him from being swept away. The boy is recovering in hospital.

As the BBC was interviewing the Rojas couple, a neighbour walked up to present them with an item salvaged from the house.

It was the teenager's money jar. The label on it read, "Leo's survival kit".

Desperate Camp Mystic parents took to social media looking for news of their children.

One Facebook group - Kerrville Breaking News - turned into a missing persons page.

Some parents have since updated their social media pleas to say their missing family members did not survive.

Kerr County is in the heart of the Texas Hill Country, a getaway destination because of its scenic rolling hills, countless rivers and lakes and abundance of wineries.

But the region is also known as "Flash Flood Alley", because of the recurring threat that has devastated local communities over the years.

When asked why the riverside summer camp was not evacuated, officials said the sudden scale of the deluge caught them unawares.

"No-one knew this kind of flood was coming," Kerr County Judge Rob Kelly said.

A frantic search for survivors is under way in central Texas after flash floods killed at least 32 people, including 14 children.

Many were asleep when the Guadalupe River rose more than 26 ft (8m) in less than an hour in the early hours of Friday.

Officials in Kerr County have said 27 children are missing from a Christian youth camp located along the river. Some 850 people were rescued.

Weather forecasts suggest that more rain and, potentially, more flooding could be on the horizon for the area.

Among the areas most severely hit by the floods were mobile homes, summer camps and camping sites where many had gathered for 4 July holiday celebrations.

At a press conference on Saturday afternoon, Texas Governor Greg Abbott said he had signed an expanded disaster declaration to boost search efforts.

• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

He said officials would be relentless in ensuring they locate "every single person who's been a victim of this event", adding that "we will stop when job is completed".

It remains a search and rescue mission, officials said, not a recovery effort.

They said rescuers were going up and down the Guadalupe River to try to find people who may have been swept away by the floods.

Much of the rescue has focused on a large all-girls Christian summer camp called Camp Mystic.

The camp, where 27 remain missing, is on the banks of the Guadalupe River near Hunt, Texas.

Texas Lieutenant Governor Dan Patrick told the BBC's Radio 4 PM programme that of the 27 children missing from Camp Mystic "many of these girls are younger girls under the age of 12".

He also said that many more people were likely to remain unaccounted for across the region, because some were visiting for the holiday weekend.

In an email to parents of the roughly 750 campers, Camp Mystic said that if they haven't been contacted directly, their child is considered missing.

Some of the families have already stated publicly that their children were among those who were found dead.

US President Donald Trump has said his administration is working closely with local authorities to respond to the emergency.

Homeland Security Secretary Kristi Noem said the president was "devastated" by the loss of life and promised full federal support.

Noem joined Governor Abbott at Saturday afternoon's press conference and said the federal government would soon be deploying the Coast Guard to help search efforts.

Elsewhere in central Texas, in Travis County, officials say another two people have died and 10 are missing because of the flooding.

Forecasters have warned that central Texas may see more flooding this weekend.

The National Weather Service (NWS) said the area could see 2 to 5in (5cm to 12cm) of rain on Saturday.

Up to 10in of rain was possible in some areas that are still reeling from Friday's deluge.

Asked last month whether he was planning to join Israel in attacking Iran, US President Donald Trump said "I may do it. I may not do it. Nobody knows what I'm going to do".

He let the world believe he had agreed a two-week pause to allow Iran to resume negotiations. And then he bombed anyway.

A pattern is emerging: The most predictable thing about Trump is his unpredictability. He changes his mind. He contradicts himself. He is inconsistent.

"[Trump] has put together a highly centralised policy-making operation, arguably the most centralised, at least in the area of foreign policy, since Richard Nixon," says Peter Trubowitz, professor of international relations at the London School of Economics.

"And that makes policy decisions more dependent on Trump's character, his preferences, his temperament."

Trump has put this to political use; he has made his own unpredictability a key strategic and political asset. He has elevated unpredictability to the status of a doctrine. And now the personality trait he brought to the White House is driving foreign and security policy.

It is changing the shape of the world.

Political scientists call this the Madman Theory, in which a world leader seeks to persuade his adversary that he is temperamentally capable of anything, to extract concessions. Used successfully it can be a form of coercion and Trump believes it is paying dividends, getting the US's allies where he wants them.

But is it an approach that can work against enemies? And could its flaw be that rather than being a sleight of hand designed to fool adversaries, it is in fact based on well established and clearly documented character traits, with the effect that his behaviour becomes easier to predict?

Attacks, insults and embraces

Trump began his second presidency by embracing Russian President Vladimir Putin and attacking America's allies. He insulted Canada by saying it should become the 51st state of the US.

He said he was prepared to consider using military force to annex Greenland, an autonomous territory of America's ally Denmark. And he said the US should retake ownership and control of the Panama Canal.

Article 5 of the Nato charter commits each member to come to the defence of all others. Trump threw America's commitment to that into doubt. "I think Article 5 is on life support" declared Ben Wallace, Britain's former defence secretary.

Conservative Attorney General Dominic Grieve said: "For now the trans-Atlantic alliance is over."

A series of leaked text messages revealed the culture of contempt in Trump's White House for European allies. "I fully share your loathing of European freeloaders," US Defence Secretary Pete Hegseth told his colleagues, adding "PATHETIC".

In Munich earlier this year, Trump's Vice-President JD Vance said the US would no longer be the guarantor of European security.

That appeared to turn the page on 80 years of trans-Atlantic solidarity. "What Trump has done is raise serious doubts and questions about the credibility of America's international commitments," says Prof Trubowitz.

"Whatever understanding those countries [in Europe] have with the United States, on security, on economic or other matters, they're now subject to negotiation at a moment's notice.

"My sense is that most people in Trump's orbit think that unpredictability is a good thing, because it allows Donald Trump to leverage America's clout for maximum gain…

"This is one of of his takeaways from negotiating in the world of real estate."

Trump's approach paid dividends. Only four months ago, Sir Keir Starmer told the House of Commons that Britain would increase defence and security spending from 2.3% of GDP to 2.5%.

Last month, at a Nato summit, that had increased to 5%, a huge increase, now matched by every other member of the Alliance.

The predictability of unpredictability

Trump is not the first American president to deploy an Unpredictability Doctrine. In 1968, when US President Richard Nixon was trying to end the war in Vietnam, he found the North Vietnamese enemy intractable.

"At one point Nixon said to his National Security Advisor Henry Kissinger, 'you ought to tell the North Vietnamese negotiators that Nixon's crazy and you don't know what he's going to do, so you better come to an agreement before things get really crazy'," says Michael Desch, professor of international relations at Notre Dame University. "That's the madman theory."

Julie Norman, professor of politics at University College London, agrees that there is now an Unpredictability Doctrine.

"It's very hard to know what's coming from day to day," she argues. "And that has always been Trump's approach."

Trump successfully harnessed his reputation for volatility to change the trans-Atlantic defence relationship. And apparently to keep Trump on side, some European leaders have flattered and fawned.

Last month's Nato summit in The Hague was an exercise in obsequious courtship. Nato Secretary General Mark Rutte had earlier sent President Trump (or "Dear Donald") a text message, which Trump leaked.

"Congratulations and thank you for your decisive action in Iran, it was truly extraordinary," he wrote.

On the forthcoming announcement that all Nato members had agreed to increase defence spending to 5% of GDP, he continued: "You will achieve something NO president in decades could get done."

Anthony Scaramucci, who previously served as Trump's communications director in his first term, said: "Mr Rutte, he's trying to embarrass you, sir. He's literally sitting on Air Force One laughing at you."

And this may prove to be the weakness at the heart of Trump's Unpredictability Doctrine: their actions may be based on the idea that Trump craves adulation. Or that he seeks short-term wins, favouring them over long and complicated processes.

If that is the case and their assumption is correct, then it limits Trump's ability to perform sleights of hand to fool adversaries - rather, he has well established and clearly documented character traits that they have become aware of.

The adversaries impervious to charm and threats

Then there is the question of whether an Unpredictability Doctrine or the Madman Theory can work on adversaries.

Ukrainian President Volodymyr Zelensky, an ally who was given a dressing down by Trump and Vance in the Oval Office, later agreed to grant the US lucrative rights to exploit Ukrainian mineral resources.

Vladimir Putin, on the other hand, apparently remains impervious to Trump's charms and threats alike. On Thursday, following a telephone call, Trump said he was "disappointed" that Putin was not ready to end the war against Ukraine.

And Iran? Trump promised his base that he would end American involvement in Middle Eastern "forever wars". His decision to strike Iran's nuclear facilities was perhaps the most unpredictable policy choice of his second term so far. The question is whether it will have the desired effect.

The former British Foreign Secretary, William Hague, has argued that it will do precisely the opposite: it will make Iran more, not less likely, to seek to acquire nuclear weapons.

Prof Desch agrees. "I think it's now highly likely that Iran will make the decision to pursue a nuclear weapon," he says. "So I wouldn't be surprised if they lie low and do everything they can to complete the full fuel cycle and conduct a [nuclear] test.

"I think the lesson of Saddam Hussein and Muammar Gaddafi is not lost on other dictators facing the US and potential regime change...

"So the Iranians will desperately feel the need for the ultimate deterrent and they'll look at Saddam and Gaddafi as the negative examples and Kim Jong Un of North Korea as the positive example."

One of the likely scenarios is the consolidation of the Islamic Republic, according to Mohsen Milani, a professor of politics at the University of South Florida and author of Iran's Rise and Rivalry with the US in the Middle East.

"In 1980, when Saddam Hussein attacked Iran his aim was the collapse of the Islamic Republic," he says. "The exact opposite happened.

"That was the Israeli and American calculation too... That if we get rid of the top guys, Iran is going to surrender quickly or the whole system is going to collapse."

A loss of trust in negotiations?

Looking ahead, unpredictability may not work on foes, but it is unclear whether the recent shifts it has yielded among allies can be sustained.

Whilst possible, this is a process built largely on impulse. And there may be a worry that the US could be seen as an unreliable broker.

"People won't want to do business with the US if they don't trust the US in negotiations, if they're not sure the US will stand by them in defence and security issues," argues Prof Norman. "So the isolation that many in the MAGA world seek is, I think, going to backfire."

German Chancellor Friedrich Merz for one has said Europe now needs to become operationally independent of the US.

"The importance of the chancellor's comment is that it's a recognition that US strategic priorities are changing," says Prof Trubowitz. "They're not going to snap back to the way they were before Trump took office.

"So yes, Europe is going to have to get more operationally independent."

This would require European nations to develop a much bigger European defence industry, to acquire kit and capabilities that currently only the US has, argues Prof Desch. For example, the Europeans have some sophisticated global intelligence capability, he says, but a lot of it is provided by the US.

"Europe, if it had to go it alone, would also require a significant increase in its independent armaments production capability," he continues. "Manpower would also be an issue. Western Europe would have to look to Poland to see the level of manpower they would need."

All of which will take years to build up.

So, have the Europeans really been spooked by Trump's unpredictability, into making the most dramatic change to the security architecture of the western world since the end of the Cold War?

"It has contributed," says Prof Trubowitz. "But more fundamentally, Trump has uncorked something… Politics in the United States has changed. Priorities have changed. To the MAGA coalition, China is a bigger problem than Russia. That's maybe not true for the Europeans."

And according to Prof Milani, Trump is trying to consolidate American power in the global order.

"It's very unlikely that he's going to change the order that was established after World War Two. He wants to consolidate America's position in that order because China is challenging America's position in that order."

But this all means that the defence and security imperatives faced by the US and Europe are diverging.

The European allies may be satisfied that through flattery and real policy shifts, they have kept Trump broadly onside; he did, after all, reaffirm his commitment to Article 5 at the most recent Nato summit. But the unpredictability means this cannot be guaranteed - and they have seemed to accept that they can no longer complacently rely on the US to honour its historic commitment to their defence.

And in that sense, even if the unpredictability doctrine comes from a combination of conscious choice and Trump's very real character traits, it is working, on some at least.

Top image credit: Getty Images

BBC InDepth is the home on the website and app for the best analysis, with fresh perspectives that challenge assumptions and deep reporting on the biggest issues of the day. And we showcase thought-provoking content from across BBC Sounds and iPlayer too. You can send us your feedback on the InDepth section by clicking on the button below.

Iconic Indian director and actor Guru Dutt was just 39 years old when he died in 1964 but he left behind a cinematic legacy that continues to resonate decades later.

Born on 9 July 1925 in the southern state of Karnataka, next week marks his birth centenary. But the man behind the camera, his emotional turmoil and mental health struggles remain largely unexplored.

Warning: This article contains details some readers may find distressing.

The maker of classic Hindi films such as Pyaasa and Kaagaz Ke Phool - film school staples for their timeless themes - Dutt forged a deeply personal, introspective style of filmmaking that was novel in the post-independence era.

His complex characters often reflected his personal struggles; his plots touched upon universal motifs, inviting the audience to confront uncomfortable realities through hauntingly beautiful cinema.

Dutt's beginnings were humble and his childhood was marked by financial hardship and a turbulent family life. After his family shifted to Bengal in eastern India for work, a young Dutt became deeply inspired by the region's culture and it would shape his cinematic vision later in life.

He dropped his surname - Padukone - after entering the Bombay film industry in the 1940s. He made his debut not as a director but as a choreographer, and also worked as a telephone operator to make ends meet. The turbulence and uncertainty of the decade - India's independence struggle had intensified - impacted the aspiring filmmaker's prospects.

It was during this phase that he penned Kashmakash, a story rooted in artistic frustration and social disillusionment, ideas that would later shape his cinematic masterpiece Pyaasa.

Dutt's friendship with fellow struggler Dev Anand - who soon rose to fame as an actor - helped him get the chance to direct his first film in 1951. The noir thriller, Baazi, propelled him into the spotlight.

He soon found love with celebrated singer Geeta Roy, and by many accounts, these early years were his happiest.

After Dutt launched his own film company, he scored back-to-back hits with romantic comedies Aar-Paar and Mr & Mrs 55, both featuring him in lead roles. But yearning for artistic depth, he set out to make what would become his defining film - Pyaasa.

The hard-hitting, haunting film explored an artist's struggle in a materialistic world and decades later, it would go on to be the only Hindi film in Time magazine's list of the 20th Century's 100 greatest movies.

Dutt's late younger sister, Lalitha Lajmi, who collaborated with me when I wrote his biography, said that Pyaasa was her brother's "dream project" and that "he wanted it to be perfect".

As a director, Dutt was fond of 'creating' the film as it took shape on the sets, making a lot of changes in the script and dialogues and experimenting with camera techniques. While he was known for scrapping and reshooting scenes, this reached worrying levels during Pyaasa - for instance, he shot 104 takes of the now famous climax sequence.

He would shout and get bad-tempered when things did not go right, Lajmi said.

"Sleep evaded him. The misuse of and dependence on alcohol had begun. At his worst, he started experimenting with sleeping pills, mixing them in his whiskey. Guru Dutt gave his all to make Pyaasa - his sleep, his dreams, and his memories," she said.

In 1956, as his dream project neared completion, 31-year-old Dutt attempted suicide.

"When the news came, we rushed to Pali Hill [where he lived]," Lajmi said. "I knew he was in turmoil. He often called me, saying we need to talk but wouldn't say a word when I got there," she added.

But following his discharge from hospital, no professional support was sought by the family.

Mental health was a "socially stigmatised" topic at the time, and with big money riding on Pyaasa, Lajmi said that the family tried to move on, without fully confronting the reasons behind her brother's internal struggles.

Released in 1957, Pyaasa was a critical and commercial triumph that catapulted Dutt to stardom. But the filmmaker often expressed a sense of emptiness despite his success.

Pyaasa's chief cinematographer VK Murthy recalled Dutt saying, "I wanted to be a director, an actor, make good films - I have achieved it all. I have money, I have everything, yet I have nothing."

There was also a strange paradox between Dutt's films and his personal life.

His films often portrayed strong, independent women but off screen, as Lajmi recalled, he expected his wife to embrace more traditional roles and wanted her to sing only in films produced by his company.

To keep his company thriving, Dutt had a simple rule: each artistic gamble should be followed by a bankable commercial film.

But buoyed by the success of Pyaasa, he ignored his own rule and dived straight into making his most personal, expensive and semi-autobiographical film: Kaagaz Ke Phool.

It tells the story of a filmmaker's unhappy marriage and confused relationship with his muse. It eerily ends with the death of the filmmaker after he fails to come to terms with his acute loneliness and doomed relationships.

Though now hailed as a classic, it was a commercial failure at the time, a blow Dutt reportedly never overcame.

In the Channel 4 documentary In Search of Guru Dutt, his co-star Waheeda Rehman remembered him saying, "Life mein do hi toh cheezen hai - kamyaabi aur failure. (There are only two things in life: success and failure) There is nothing in between."

After Kagaz Ke Phool, he never directed a film again.

But his company recovered over time, and he made a strong comeback as a producer with Chaudhvin Ka Chand, the most commercially successful film of his career.

He then launched Sahib Bibi Aur Ghulam directed by his trusted screenwriter Abrar Alvi. By this time, Lajmi said, his personal life was in severe turmoil, marked by mood swings.

The film delved into the loneliness of a woman trapped in a loveless marriage to a philandering, often tyrannical landlord in an opulent yet feudal world.

Writer Bimal Mitra recalls that Dutt told him about his struggle with sleeplessness and reliance on sleeping pills during this time. By then, his marriage had collapsed and mental health had worsened. Mitra recalled many conversations with Guru Dutt's constant refrain: "I think I will go crazy."

One night, Dutt attempted to take his own life again. He was unconscious for three days.

Lajmi says that after this, on the doctor's advice, his family called a psychiatrist to inquire about treatment for Dutt but they never followed up. "We never called the psychiatrist again," she added with regret.

For years, she believed her brother was silently crying for help, perhaps feeling trapped in a dark space where no one could see his pain, so dark that even he could not find a way out of it.

A few days after Dutt was discharged, the shooting for Sahib Bibi Aur Ghulam resumed as if nothing had happened.

When Mitra asked him about the incident, Dutt said, "Nowadays, I often wonder what unrest was this, what was the restlessness that I was hell-bent on committing suicide? When I think about this, I get terrorised with fear. But that day, I felt no dilemma in swallowing those sleeping pills."

The film was a success, became India's official entry to the 1963 Berlin Film Festival and also won a national award.

But Dutt's personal struggles continued to mount. He separated from his wife and even though he continued acting in films, he battled profound loneliness, often turning to alcohol and sleeping pills for respite.

On 10 October 1964, Dutt, 39, was found dead in his room.

"I know that he had always wished for it [death], longed for it... and he got it,' his co-star Waheeda Rehman wrote in the Journal of Film Industry, 1967.

Like the protagonist of Pyaasa, true acclaim came to Dutt only after he was gone.

Cinema enthusiasts often wonder what might have been had he lived longer; perhaps he would have continued to reshape India's cinematic landscape with his visionary, poetic works.

Yasser Usman is the author of the biography Guru Dutt: An Unfinished Story

A frantic search for survivors is under way in central Texas after flash floods killed at least 32 people, including 14 children.

Many were asleep when the Guadalupe River rose more than 26 ft (8m) in less than an hour in the early hours of Friday.

Officials in Kerr County have said 27 children are missing from a Christian youth camp located along the river. Some 850 people were rescued.

Weather forecasts suggest that more rain and, potentially, more flooding could be on the horizon for the area.

Among the areas most severely hit by the floods were mobile homes, summer camps and camping sites where many had gathered for 4 July holiday celebrations.

At a press conference on Saturday afternoon, Texas Governor Greg Abbott said he had signed an expanded disaster declaration to boost search efforts.

• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

He said officials would be relentless in ensuring they locate "every single person who's been a victim of this event", adding that "we will stop when job is completed".

It remains a search and rescue mission, officials said, not a recovery effort.

They said rescuers were going up and down the Guadalupe River to try to find people who may have been swept away by the floods.

Much of the rescue has focused on a large all-girls Christian summer camp called Camp Mystic.

The camp, where 27 remain missing, is on the banks of the Guadalupe River near Hunt, Texas.

Texas Lieutenant Governor Dan Patrick told the BBC's Radio 4 PM programme that of the 27 children missing from Camp Mystic "many of these girls are younger girls under the age of 12".

He also said that many more people were likely to remain unaccounted for across the region, because some were visiting for the holiday weekend.

In an email to parents of the roughly 750 campers, Camp Mystic said that if they haven't been contacted directly, their child is considered missing.

Some of the families have already stated publicly that their children were among those who were found dead.

US President Donald Trump has said his administration is working closely with local authorities to respond to the emergency.

Homeland Security Secretary Kristi Noem said the president was "devastated" by the loss of life and promised full federal support.

Noem joined Governor Abbott at Saturday afternoon's press conference and said the federal government would soon be deploying the Coast Guard to help search efforts.

Elsewhere in central Texas, in Travis County, officials say another two people have died and 10 are missing because of the flooding.

Forecasters have warned that central Texas may see more flooding this weekend.

The National Weather Service (NWS) said the area could see 2 to 5in (5cm to 12cm) of rain on Saturday.

Up to 10in of rain was possible in some areas that are still reeling from Friday's deluge.

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A frantic search for survivors is under way in central Texas after flash floods killed at least 32 people, including 14 children.

Many were asleep when the Guadalupe River rose more than 26 ft (8m) in less than an hour in the early hours of Friday.

Officials in Kerr County have said 27 children are missing from a Christian youth camp located along the river. Some 850 people were rescued.

Weather forecasts suggest that more rain and, potentially, more flooding could be on the horizon for the area.

Among the areas most severely hit by the floods were mobile homes, summer camps and camping sites where many had gathered for 4 July holiday celebrations.

At a press conference on Saturday afternoon, Texas Governor Greg Abbott said he had signed an expanded disaster declaration to boost search efforts.

• Texas flood victims: Girl 'living her best life' and 'heart and soul' of camp

He said officials would be relentless in ensuring they locate "every single person who's been a victim of this event", adding that "we will stop when job is completed".

It remains a search and rescue mission, officials said, not a recovery effort.

They said rescuers were going up and down the Guadalupe River to try to find people who may have been swept away by the floods.

Much of the rescue has focused on a large all-girls Christian summer camp called Camp Mystic.

The camp, where 27 remain missing, is on the banks of the Guadalupe River near Hunt, Texas.

Texas Lieutenant Governor Dan Patrick told the BBC's Radio 4 PM programme that of the 27 children missing from Camp Mystic "many of these girls are younger girls under the age of 12".

He also said that many more people were likely to remain unaccounted for across the region, because some were visiting for the holiday weekend.

In an email to parents of the roughly 750 campers, Camp Mystic said that if they haven't been contacted directly, their child is considered missing.

Some of the families have already stated publicly that their children were among those who were found dead.

US President Donald Trump has said his administration is working closely with local authorities to respond to the emergency.

Homeland Security Secretary Kristi Noem said the president was "devastated" by the loss of life and promised full federal support.

Noem joined Governor Abbott at Saturday afternoon's press conference and said the federal government would soon be deploying the Coast Guard to help search efforts.

Elsewhere in central Texas, in Travis County, officials say another two people have died and 10 are missing because of the flooding.

Forecasters have warned that central Texas may see more flooding this weekend.

The National Weather Service (NWS) said the area could see 2 to 5in (5cm to 12cm) of rain on Saturday.

Up to 10in of rain was possible in some areas that are still reeling from Friday's deluge.

Asked last month whether he was planning to join Israel in attacking Iran, US President Donald Trump said "I may do it. I may not do it. Nobody knows what I'm going to do".

He let the world believe he had agreed a two-week pause to allow Iran to resume negotiations. And then he bombed anyway.

A pattern is emerging: The most predictable thing about Trump is his unpredictability. He changes his mind. He contradicts himself. He is inconsistent.

"[Trump] has put together a highly centralised policy-making operation, arguably the most centralised, at least in the area of foreign policy, since Richard Nixon," says Peter Trubowitz, professor of international relations at the London School of Economics.

"And that makes policy decisions more dependent on Trump's character, his preferences, his temperament."

Trump has put this to political use; he has made his own unpredictability a key strategic and political asset. He has elevated unpredictability to the status of a doctrine. And now the personality trait he brought to the White House is driving foreign and security policy.

It is changing the shape of the world.

Political scientists call this the Madman Theory, in which a world leader seeks to persuade his adversary that he is temperamentally capable of anything, to extract concessions. Used successfully it can be a form of coercion and Trump believes it is paying dividends, getting the US's allies where he wants them.

But is it an approach that can work against enemies? And could its flaw be that rather than being a sleight of hand designed to fool adversaries, it is in fact based on well established and clearly documented character traits, with the effect that his behaviour becomes easier to predict?

Attacks, insults and embraces

Trump began his second presidency by embracing Russian President Vladimir Putin and attacking America's allies. He insulted Canada by saying it should become the 51st state of the US.

He said he was prepared to consider using military force to annex Greenland, an autonomous territory of America's ally Denmark. And he said the US should retake ownership and control of the Panama Canal.

Article 5 of the Nato charter commits each member to come to the defence of all others. Trump threw America's commitment to that into doubt. "I think Article 5 is on life support" declared Ben Wallace, Britain's former defence secretary.

Conservative Attorney General Dominic Grieve said: "For now the trans-Atlantic alliance is over."

A series of leaked text messages revealed the culture of contempt in Trump's White House for European allies. "I fully share your loathing of European freeloaders," US Defence Secretary Pete Hegseth told his colleagues, adding "PATHETIC".

In Munich earlier this year, Trump's Vice-President JD Vance said the US would no longer be the guarantor of European security.

That appeared to turn the page on 80 years of trans-Atlantic solidarity. "What Trump has done is raise serious doubts and questions about the credibility of America's international commitments," says Prof Trubowitz.

"Whatever understanding those countries [in Europe] have with the United States, on security, on economic or other matters, they're now subject to negotiation at a moment's notice.

"My sense is that most people in Trump's orbit think that unpredictability is a good thing, because it allows Donald Trump to leverage America's clout for maximum gain…

"This is one of of his takeaways from negotiating in the world of real estate."

Trump's approach paid dividends. Only four months ago, Sir Keir Starmer told the House of Commons that Britain would increase defence and security spending from 2.3% of GDP to 2.5%.

Last month, at a Nato summit, that had increased to 5%, a huge increase, now matched by every other member of the Alliance.

The predictability of unpredictability

Trump is not the first American president to deploy an Unpredictability Doctrine. In 1968, when US President Richard Nixon was trying to end the war in Vietnam, he found the North Vietnamese enemy intractable.

"At one point Nixon said to his National Security Advisor Henry Kissinger, 'you ought to tell the North Vietnamese negotiators that Nixon's crazy and you don't know what he's going to do, so you better come to an agreement before things get really crazy'," says Michael Desch, professor of international relations at Notre Dame University. "That's the madman theory."

Julie Norman, professor of politics at University College London, agrees that there is now an Unpredictability Doctrine.

"It's very hard to know what's coming from day to day," she argues. "And that has always been Trump's approach."

Trump successfully harnessed his reputation for volatility to change the trans-Atlantic defence relationship. And apparently to keep Trump on side, some European leaders have flattered and fawned.

Last month's Nato summit in The Hague was an exercise in obsequious courtship. Nato Secretary General Mark Rutte had earlier sent President Trump (or "Dear Donald") a text message, which Trump leaked.

"Congratulations and thank you for your decisive action in Iran, it was truly extraordinary," he wrote.

On the forthcoming announcement that all Nato members had agreed to increase defence spending to 5% of GDP, he continued: "You will achieve something NO president in decades could get done."

Anthony Scaramucci, who previously served as Trump's communications director in his first term, said: "Mr Rutte, he's trying to embarrass you, sir. He's literally sitting on Air Force One laughing at you."

And this may prove to be the weakness at the heart of Trump's Unpredictability Doctrine: their actions may be based on the idea that Trump craves adulation. Or that he seeks short-term wins, favouring them over long and complicated processes.

If that is the case and their assumption is correct, then it limits Trump's ability to perform sleights of hand to fool adversaries - rather, he has well established and clearly documented character traits that they have become aware of.

The adversaries impervious to charm and threats

Then there is the question of whether an Unpredictability Doctrine or the Madman Theory can work on adversaries.

Ukrainian President Volodymyr Zelensky, an ally who was given a dressing down by Trump and Vance in the Oval Office, later agreed to grant the US lucrative rights to exploit Ukrainian mineral resources.

Vladimir Putin, on the other hand, apparently remains impervious to Trump's charms and threats alike. On Thursday, following a telephone call, Trump said he was "disappointed" that Putin was not ready to end the war against Ukraine.

And Iran? Trump promised his base that he would end American involvement in Middle Eastern "forever wars". His decision to strike Iran's nuclear facilities was perhaps the most unpredictable policy choice of his second term so far. The question is whether it will have the desired effect.

The former British Foreign Secretary, William Hague, has argued that it will do precisely the opposite: it will make Iran more, not less likely, to seek to acquire nuclear weapons.

Prof Desch agrees. "I think it's now highly likely that Iran will make the decision to pursue a nuclear weapon," he says. "So I wouldn't be surprised if they lie low and do everything they can to complete the full fuel cycle and conduct a [nuclear] test.

"I think the lesson of Saddam Hussein and Muammar Gaddafi is not lost on other dictators facing the US and potential regime change...

"So the Iranians will desperately feel the need for the ultimate deterrent and they'll look at Saddam and Gaddafi as the negative examples and Kim Jong Un of North Korea as the positive example."

One of the likely scenarios is the consolidation of the Islamic Republic, according to Mohsen Milani, a professor of politics at the University of South Florida and author of Iran's Rise and Rivalry with the US in the Middle East.

"In 1980, when Saddam Hussein attacked Iran his aim was the collapse of the Islamic Republic," he says. "The exact opposite happened.

"That was the Israeli and American calculation too... That if we get rid of the top guys, Iran is going to surrender quickly or the whole system is going to collapse."

A loss of trust in negotiations?

Looking ahead, unpredictability may not work on foes, but it is unclear whether the recent shifts it has yielded among allies can be sustained.

Whilst possible, this is a process built largely on impulse. And there may be a worry that the US could be seen as an unreliable broker.

"People won't want to do business with the US if they don't trust the US in negotiations, if they're not sure the US will stand by them in defence and security issues," argues Prof Norman. "So the isolation that many in the MAGA world seek is, I think, going to backfire."

German Chancellor Friedrich Merz for one has said Europe now needs to become operationally independent of the US.

"The importance of the chancellor's comment is that it's a recognition that US strategic priorities are changing," says Prof Trubowitz. "They're not going to snap back to the way they were before Trump took office.

"So yes, Europe is going to have to get more operationally independent."

This would require European nations to develop a much bigger European defence industry, to acquire kit and capabilities that currently only the US has, argues Prof Desch. For example, the Europeans have some sophisticated global intelligence capability, he says, but a lot of it is provided by the US.

"Europe, if it had to go it alone, would also require a significant increase in its independent armaments production capability," he continues. "Manpower would also be an issue. Western Europe would have to look to Poland to see the level of manpower they would need."

All of which will take years to build up.

So, have the Europeans really been spooked by Trump's unpredictability, into making the most dramatic change to the security architecture of the western world since the end of the Cold War?

"It has contributed," says Prof Trubowitz. "But more fundamentally, Trump has uncorked something… Politics in the United States has changed. Priorities have changed. To the MAGA coalition, China is a bigger problem than Russia. That's maybe not true for the Europeans."

And according to Prof Milani, Trump is trying to consolidate American power in the global order.

"It's very unlikely that he's going to change the order that was established after World War Two. He wants to consolidate America's position in that order because China is challenging America's position in that order."

But this all means that the defence and security imperatives faced by the US and Europe are diverging.

The European allies may be satisfied that through flattery and real policy shifts, they have kept Trump broadly onside; he did, after all, reaffirm his commitment to Article 5 at the most recent Nato summit. But the unpredictability means this cannot be guaranteed - and they have seemed to accept that they can no longer complacently rely on the US to honour its historic commitment to their defence.

And in that sense, even if the unpredictability doctrine comes from a combination of conscious choice and Trump's very real character traits, it is working, on some at least.

Top image credit: Getty Images

BBC InDepth is the home on the website and app for the best analysis, with fresh perspectives that challenge assumptions and deep reporting on the biggest issues of the day. And we showcase thought-provoking content from across BBC Sounds and iPlayer too. You can send us your feedback on the InDepth section by clicking on the button below.