A highly purified form of uranium is needed to make an atomic bomb, but the main point of Tehran’s action may be to give it leverage in nuclear talks.

A new book about the Pech Valley in Afghanistan’s violent east offers poignant lessons as the Biden administration announces plans to withdraw all troops.

Blue states have pulled far ahead of red states in vaccinations. Why?

“There are vaccines like polio where one dose is enough, and there are vaccines like flu that you need every year, ” Pfizer’s chief said. “The Covid virus looks more like the influenza virus than the polio virus.”

Roadblocks abound, but airlines, hotels and tour companies are trying to balance optimism with caution.

Prison sentences for prominent pro-democracy leaders over unauthorized peaceful protest point to what critics say is the shrinking space for dissent in Hong Kong.

Readers reflect on the country’s many different accents.

U.S. sanctions on Russia.

After four years of Donald J. Trump’s America-first mantra, Republican views on foreign intervention, long a signature part of the party’s brand, have splintered.

A Treasury Department document shed more light on links between the campaign and Russian spies.