Also when the world mostly ignored The Armenian Genocide, that convinced Hitler that eliminating the Jews wasn’t all that big of a deal.
Absolutely. People do people things. The Jewish Holocaust was unquestionably bad — but it was not a new thing. It was not unique. The Armenian Genocide, Stalin’s Holodomor, Rwanda, Mao’s Great Leap — these things happened either before Hitler or After Hitler. We just keep doing the same bad things. And most of the time, the Bad Leaders get away with it, which makes the next Guy think he can also get away with it.