Russian President Vladimir Putin is fond of nuclear saber-rattling: On the eve of Russia’s full-scale invasion of Ukraine in February 2022, the Kremlin leader presided over the rehearsal of a nuclear strike,

President Vladimir V. Putin heightened his warnings against the West, asserting that Russia should be permitted to use nuclear arms in the event of an attack by a nation backed by a nuclear power.

Putin has extended the list of scenarios that could lead to Russia using nuclear weapons. Whether he means it is a question critical to the course of the war. If he is serious, the conflict could turn into World War Three.