North Korea has restarted reactor to make plutonium, fresh images suggest. China military official says war with US under Donald Trump “becoming practical reality”. Jeffrey Lin and P.W. Singer on the nuclear arsenals of China and the U.S.: Plans for a future armageddon. A forgotten fact: In 1969, Russia and China almost went to war (and it could have gone nuclear). From the Bulletin of the Atomic Scientists, a first look at a 21st century disarmament movement; can a treaty banning nuclear weapons speed their abolition? Arms control is realistic; general disarmament probably isn't. Reality: Humanity can't indefinitely avoid using nuclear weapons.

Thanks to Trump, the Doomsday Clock advances toward midnight. Derek Hawkins on the history of the Doomsday Clock as it moves closer to “midnight”. Jon Wolfsthal on thinking beyond the next nuclear tweet.