Putin's irrationality is his insistence that Russia can take on the US as a major imperial player. Whatever you think of US imperialism (not a huge fan, personally) the reality is that the US is a hegemon which has the resources to run the largest military and intelligence operations on the planet.

Russia isn't, and doesn't. Russia isn't even close. So it uses political subversion instead of outright militarism. Which - it turns out - is possibly the one domain where it's competitive with the US. For not all that much money, some info war campaigns, and the help of internal allies, Russia almost got itself a two term president with eyes on a permanent dictatorship.

Nice plan. Didn't quite work.

But Putin decided to go ahead anyway. Which is insane. Every single goal - weakening NATO, weakening the EU, building closer relationships with China, India, and Turkey, strengthening Russia internally, cementing his own position in history as Tsar Vladimir I, saviour of the Empire - has failed, disastrously and counterproductively.

So now Putin has two choices. Admit defeat and have an unfortunate accident with a window, or burn everything to the ground out of spite and frustration.

He's not going for Option 1. So it's up to everyone else to make sure Option 2 doesn't happen.