Versaille played a role, the Nazi's used, and the reparations, for propaganda. WW1 and WW2 were different so, as in WW1 a lot less genozide happened. What was very convinient for both, Allies and Axis, was the coming cold war. It allowed them to quickly forego the necessary clean-up work of Germany, an ugly and lengthy thing, and just go and use former Nazis to continue the "good fight against Communism".

That the Allies choose the Marshall over the Morgenthau plan was a good call so, even if the former would have worked as well including a complete purge of Nazis from Germany.