This really deserves more attention than it is receiving:

Mr. Putin said, Russia would treat “aggression against Russia by any nonnuclear state, but with the participation or support of a nuclear state” as a “joint attack on the Russian Federation.” The language was a clear reference to Ukraine, which does not have nuclear weapons, and the military support it receives from nuclear-armed NATO countries like the United States and Britain.

Mr. Putin also said that Russia would be prepared to use a nuclear weapon even in response to an attack carried out with conventional weapons that creates “a critical threat to our sovereignty.” Ukraine last month pressed a cross-border offensive that captured territory in Russia for the first time since the war began and has been lobbying Washington for permission to use Western missiles for strikes deep into Russian territory.

While I do not expect Russia to launch a nuclear first strike on the U.S. or U.K., I worry that he may use tactical nuclear weapons against Ukraine, and once that happens, things could spin out of control very quickly.