Nuclear weapons, whale sharks, and how to use both to make eco-tourism more sustainable.

MIT team successfully tests a new method for verification of weapons reduction.

Russia urges villagers to leave nuclear fallout area and then tells them to come back.

For the Japanese in World War II, surrender was unthinkable. So unthinkable that many soldiers continued to fight even after the island nation eventually did surrender.

Russia's famed intelligence agency was often successful in getting American secrets.

These photos of scientific heroes and accomplishments inspire awe and curiosity.

Russia has launched several so-called "inspector satellites" that could potentially be weaponized.

On Tuesday, Secretary of State Mike Pompeo said the U.S. will withdraw from the 1987 agreement unless Russia falls back into compliance.

The incredible story of a scientist who survived gulags, fighting to change his country and physics.

Are we standing on the brink of Mutually Assured Destruction?

Want to tax corporations without scaring them off, outsmart a calculating kid, or get rid of the world's nuclear warheads? Think like a game theorist.

What's really involved in snuffing out a country’s nuclear capabilities—and is that the right war to be waging?

There's a deep psychological reason that America treats nuclear weapons like a spoiled child hogging all the neighborhood candy. Are we too paranoid to see it?

North Korea has a long history of making bellicose threats that defy global norms. So does that mean the country's leaders are irrational, and will act irrationally?

A Washington think tank raises concerns that U.S. nuclear weapons stored at a military base in Turkey can fall into the wrong hands.