In the 1930s, Adolf Hitler believed that his great-power rivals would be easy to exploit and isolate because each had little interest in fighting Ger… - John Mearsheimer

Important benefits often accrue to states that behave in an unexpected way.

We have a huge amount of evidence that it was nato expansion and the more general policy of making Ukraine a western bulwark on Russia’s border that motivated him to attack on February 24th... For Putin to have said time after time that nato, that Ukraine in nato, was an existential threat to Russia, when in fact it wasn’t, and this was all done to disguise the real motive, which was to incorporate Ukraine into a greater Russia for the purposes of satisfying his imperial ambitions is an argument that is just not supported by the historical record. Putin was very clear, as were all his lieutenants, that their great fear was that Ukraine was becoming a Western bulwark on Russia’s borders. For them, that was an existential threat. It was simply unacceptable.

... after the war, he became a big proponent of the argument that chemical warfare or gas warfare was actually a more humane form of warfare than shrapnel and bombs, because he saw what all those shrapnel and bombs did to all the boys who climbed out of the trenches and tried to cross no man's land, with German machine guns and artillery on the other side, he said I'll take the gas any day. I'm not making the case for gas warfare, but the idea that getting killed by gas is, more horrible than getting ripped apart by shrapnel and bullets is not one I buy. And when I see the Obama administration putting pictures of people killed by gas up on the internet, I say "let's put pictures of the people who got killed by shrapnel up there, and lets have a debate about which pictures look worse". It won't even be an interesting debate, getting killed by shrapnel, in my opinion is a lot more gruesome and a lot worse.