With Germany losing even more territory, infact being split in 4, being made to pay more reparations, and having to reorient its economy, how come no party exploited those restrictions to their benefit like after the Treaty of Versailles?
Following World War I, Germany was forced to take the blame and basically left on their own to survive, or not. Following World War II, Germany was split into four zones, occupied by the victorious Allied powers: The United States, Britain, France, and the Soviet Union. The first three essentially merged their zones into what became West Germany, allowing industry to recovery without as many reparations as the first war. With the onset of the Cold War and the grip the Soviet Union had over Eastern Europe, there was little any dictator who wasn't "friendly" toward the Soviets could do. Plus, you have the international backing of the United States, Britain, and many others with the creation of the United Nations. All of this was done to make sure Germans did not resort to extremism as they had after World War I. Hope I helped!
After WW1 Germany was punished and left to fend for itself. Poverty, economic chaos and disillusionment that marked much of the Weimar Republic era was a fermenting ground for dissent and extremism. Possibly the lack of a direct military defeat left the theories open that the was mishandled rather than lost.
Wiser heads after WW2 recognised that to prevent a repeat then perhaps some degree of social prosperity is required. When people are fed and feel hope they are less inclined to extremism. The Allies were smart enough to control Germany and helped rebuild it, thus stabilising the political situation and making a war-weary populace inclined to more moderate desires for their future.
I also think it was part of Americas plan to ensure the land war of WW3, if it came, was largely fought on German soil.
Possibly, although you'd need to support it with some substantial evidence (which I dont have ), the near total destruction of WW2 (and not so long after WW!) and the acts of the Holocaust, may have dampened any enthusiam for extremism and shocked the populace out of their previous nationalistic militarism. Certainly the post WW2 Germany appears to be quite a different beast than the earlier versions.