>https://www.thefirstnews.com/article/first-strike-how-the-po...
Additionally, after remilitarization, there were more opportunities to Strike. Rhineland, Anschluss of Austria... the longer you wait it's worse.
>I also heard that appeasement was backreaction to WW1, where everybody was eager to go to war and it ended in bloodshed.
Wehrmacht was not close to being combat ready yet, and would get crushed by combined Polish-Czechoslovakian-Western Allies troops. Without Czechoslovakia opposing them, and Czech industry fully contributing to Hitler's war machine odds were drastically better for Nazis. https://en.wikipedia.org/wiki/Panzer_38(t)
>However, objectively, I don't think Czechs defending (like the Ukraine chose to) would save more human lives.
And Ukraine is winning the war, saving 40 million Ukrainians from genocide.
That's actually very uncertain. If the war broke out, Hitler might get overthrown: https://en.wikipedia.org/wiki/Oster_conspiracy
Hitler's position was shaky at the time, but his success in Czechoslovakia made any opposition impossible and increased hunger for more.
And arguably in the case of Ukraine the appeasement already happened after 2014 Donetsk war.
I also heard that appeasement was backreaction to WW1, where everybody was eager to go to war and it ended in bloodshed.