“Snapback” sanctions will be triggered by the end of August if Tehran fails to make concrete progress to limit its nuclear program.

© Maxar Technologies, via Reuters

Readers respond to the president’s latest turn in the war. Also: President Trump and Rosie O’Donnell; New Yorkers’ health; travel medical kits.

Pentagon officials said details were still being worked out, and experts doubted Mr. Trump’s threat of huge tariffs for Russian trading partners.

© Tyler Hicks/The New York Times

The president also warned Russia that he would impose a new round of punishing sanctions if it did not agree to a peace deal within 50 days.

© Doug Mills/The New York Times

New payment systems allow users and banks to bypass the U.S. currency and sanctions.

New payment systems allow users and banks to bypass the U.S. currency and sanctions.

The alliance of emerging economies hopes to offer a counterweight to the United States and other Western powers. But military strikes on Iran are testing its unity.

The Kalma Beach resort town, one of Kim Jong-un’s most ambitious projects aimed at attracting foreign tourists, may not draw the waves of visitors he wants.

China has become trendy for Russians who once worshiped everything Western. Young people are learning Mandarin, and Chinese culture and goods have become ubiquitous in Moscow.

China has become trendy for Russians who once worshiped everything Western. Young people are learning Mandarin, and Chinese culture and goods have become ubiquitous in Moscow.

Someday the regime will crack and people power will prevail. I suspect that will be more likely when there’s peace.

Iran’s retaliation against Israel’s attacks Friday raised concerns that a broader Middle East conflict would disrupt the world’s energy supplies and stoke inflation.

The military strikes jolted investors, raising concerns that a broader Mideast conflict would disrupt the world’s energy supplies.

Under three presidential administrations, officials in Washington have used export controls to hold back China’s access to advanced technology.

Experts and former officials said it was unusual for a cabinet secretary to try to influence the Treasury Department’s sanctions process to target a domestic entity.

China has leverage it can use by limiting access to its rare earth supplies, but it does not want to sacrifice its reputation as a reliable supplier.

Experts and former officials said it was unusual for a cabinet secretary to try to influence the Treasury Department’s sanctions process to target a domestic entity.

China produces the entire world’s supply of samarium, a rare earth metal that the United States and its allies need to rebuild inventories of fighter jets, missiles and other hardware.

Since early April, China has stopped almost all shipments of critical minerals that are needed for cars, robots, wind turbines, jet fighters and other technologies.

The United States allowed its rare earth metals industry to move to China and could now face severe economic disruption as China limits crucial supplies.

Just two and a half weeks after agreeing to suspend tariffs, both countries are using export controls to disrupt each other’s key industries.