Atomic weapons are an extinction-level threat, so you’d ideally want a steady hand guiding U.S. nuclear policy. Instead, we have Donald Trump—and boy has he made the past two days tense. Yesterday, the Trump administration signed an accord to give Saudi Arabia a nuclear energy program.

The National Nuclear Security Administration (NNSA) said it completed ‘Diamond stamping' of the new B61-13 nuclear bomb, meaning it has met all the requirements of the rigorous certification process.

Iran says its nuclear program is for peaceful purposes such as energy, research, and medical uses. Under the Nuclear Non-Proliferation Treaty, Iran is allowed to pursue civilian nuclear activities, including uranium enrichment, as long as those activities ...

Henry Kissinger often said that nuclear arms are “weapons in search of a doctrine.” After the Cold War, some strategists have tried to figure out what, exactly, these weapons could buy them beyond deterrence.

Civilization faces at least two existential crises. One of them, global warming, is happening now and will worsen throughout this century. The other is highly uncertain and could strike today. If it happens,