Russia's new nuclear weapons are technically plausible...

ON MARCH 1st, addressing Russia's parliament, President Vladimir Putin announced a range of new, high-tech, "invincible" nuclear weapons. Lest anyone was unsure at whom that part of the speech was aimed, it featured a computer-generated animation of nukes falling on Florida, where Donald Trump, America's president, has his Mar-a-Lago resort. Mr Putin's new weapons included nuclear-powered, nuclear-tipped cruise missiles with nearly infinite range and nuclear-armed underwater drones designed to c...