Lt. Gen. Dan Caine will serve as the senior military adviser to President Trump and Defense Secretary Pete Hegseth.

© Kenny Holston/The New York Times

His predecessor as defense secretary, Lloyd J. Austin III, started the roughly 50-nation group to support Kyiv after Russia invaded in 2022, but Mr. Hegseth has given up leadership.

© Eric Lee/The New York Times

Striking the Iranian-backed Houthi militia serves United States interests, and puts pressure on Iran over its nuclear ambitions.

America is in a period of profound national regression. Where will the country end up?

From tariffs to ballots, he makes up his own rules.

Responses to the mass firings in the federal government. Also: Cory Booker’s speech; talk of a third Trump term; Republicans and Ukraine; a letter to Canada.

Reports that the defense secretary shared sensitive information on an unclassified messaging app are straining the limits of his credibility.

The drills came after Taiwan’s president, Lai Ching-te, announced measures to counter China’s influence and espionage. Beijing also wants to send a message to Washington, analysts said.

A politicized military is an ineffective military.

They may be even more serious than the one we’ve been focused on.

Trust your staff, admit mistakes, don’t embarrass the president.

A national security scandal is manageable. A bunker mentality spells doom.

At his first stop in the Philippines, the U.S. defense secretary promised to strengthen deterrence against Chinese “threats” in the region. He also plans to visit Japan.

The Signal group chat is only the latest in a string of self-inflicted wounds by the new administration.

Europeans are used to the Trump administration’s scorn by now, but the Signal chat’s lack of seriousness, including its substance, was shocking.

Pete Hegseth & Co. weren’t chosen for their competence.

In Trump world, the rules apply only to other people.

If there’s no real accountability for the Signal breach or even an admission of the actual problem, there’s no indication it won’t happen again.

Readers react to the security lapse that allowed the editor of The Atlantic into a group chat about a U.S. military operation in Yemen.

Help yourself. The door is open.

What members of the administration can no longer effectively do is pretend that their incompetent and reckless actions didn’t happen. It’s right there on the page.

Instead of clinging to power, he could step down honorably from his leadership role, setting an example for his party and the country.

And why the careless secretary of defense should resign.

A defense secretary intentionally using a civilian app to share sensitive war plans without noticing a journalist was in the chat would be egregious.

The president also denied a report that such a briefing had been planned to be held at the Pentagon on Friday.

The access would be a major expansion of Elon Musk’s government role and highlight his conflicts of interest.

The unusual deployment by three navy ships over the past month has prompted a debate in Australia about its aging fleet and reliance on the United States.