You know what worked even worse? Not taking the Germans seriously after WWI and trying to destabilise their country - much like what the US strategy appears to be when dealing with the world power with the largest nuclear arsenal.

The odds of Putin deciding to do a Hitler are lower than the odds of the US installing a Hitler in Russia with some sort of ill-advised regime change exercise or economic pressure campaign. The strategy that has worked multiple times is encouraging economic prosperity as soon as possible, and promoting stable government even if they aren't very good. Long lived dictators generally aren't interested in stirring up major catastrophes that will lead to them dying.

And if the US hadn't spent the last few decades marching NATO's borders towards Moscow the Russian army would probably not be in Ukraine today, following similar logic. There is no need to start fighting if there was no threat and the Ukraine government had held together through 2014.