Crimea is Sudetenland, but Ukraine is more like rump Czechoslovakia. I don't have problem with the principle that a country has broad latitude to handle intern

Crimea is Sudetenland, but Ukraine is more like rump Czechoslovakia. I don't have problem with the principle that a country has broad latitude to handle internal affairs in its own way. Nor a country, within limits, seeking to project power in its neighborhood. The principle of self-determination, as articulated by Wilson's Fourteen Principles a century ago, is very difficult to reconcile with condemning too heavily the Russian majority of Crimea seeking to leave Ukraine and rejoining Russia. The current invasion of Ukraine is different. As for why Putin (I would have written Russia, except based on many news reports it seems like Putin made this decision alone, shocking/amazing everyone around him) invaded Ukraine: I don't know. Putin's own words indicate a goal of rebuilding the physical USSR, but there is a good case to be made that Russia was strengthened after 1991 by losing chunks on the outer edges peopled by non-Russian ethnic groups. (Chechnya being an example of a chunk that it really ought to have lost.) NATO expansion isn't a satisfactory answer, either. NATO has bordered Russia since Norway became a charter member in 1949. Russia wasn't thrilled about Poland joining NATO but it seemed to be able to live with it, and one is hard pressed to say that NATO is actually strengthened by having the likes of Montenegro as members. Everyone knew that Ukraine wasn't going to be allowed to join NATO as long as the Crimea and eastern Ukraine territorial situations remained, so in practice Ukraine was permanently blocked. So why this war? At least Hitler could cite lebensraum for rump Czechoslovakia, even without the ethnic Germans that had justified taking the Sudetenland. But no one thinks that Russia, whose population is shrinking anyway, needs more space. The only two things I can think of are: * Russia feels the need to expand its borders and build buffer zones as much as possible before its demographic crisis really hits in a few years and the country can no longer staff its military. (Peter Zeihan has talked about this for years.) * Putin really has, as Macron and others have observed/hinted, gone crazy.