I see rationality in what you say in principle, but the window of opportunity for applying that method was lost in nineties, after the West disengaged from trying to make Russia a normal country, and left it to become a rouge state.
The West stopped propping up democratic politicians in Russia shortly after they felt that "job's done," and, bizarrely to 16 years old me 15 years ago, started working for the anti-democratic camp. What's the point I asked myself? And this was the time when I discovered the "our bastard" theory, practised religiously by some Western politicians.
Similarly to how Putin turned into "our bastard" for the West 20 years ago, NSDAPers were once propped up into power on hopes of getting pliable "our bastards" for major powers in light of their own problems.
Other than that, most scholars would disagree: the treatment of Germany after WWI (notably no destruction due to the war, Germany capitulated before the war reached German borders) in Versailles is what made Hitler's rise possible in the first place.
Rebuilding (Marshall plan) rather than destroying (Morgenthau plan) made Germany what it is today after WWII. Japan shows that one could have skipped the whole 2nd act in Europe: Japan wasn't destroyed at all, but rebuilt after WWII, and seized to be a threat to the world.