So "we" should not allow other countries to produce Hitlers and Mussolinis?
Allow? In the case of Hitler, it was more like aid and abet.
At the end of the First World War, the Germans laid down their arms based upon agreed terms. Then the French insisted upon altering those terms to something far more harshly punitive. The USA was the 800-pound gorilla in the room, and could have prevented this, but did not, because the destruction of the German economy would allow US corporations to buy up German assets for pennies on the dollar. And if this reminds you of what was done to Argentina at the end of the Malvinas War, then you win a gold star.
But the destruction of the German economy also set the stage for the rise of National Socialism.
In the 1930's, many US corporations, (including the nascent Bush Family empire), were heavily invested in German industry. Ford Motor Company bought a controlling interest in Opel as late as the mid-30's. And Opel manufactured the trucks which converted the German leg infantry to motorised infantry. All of this was done, could only have been done, with the at-least-tacit agreement of the US government.
But of course they don't teach us any of this in high school, or even college. Because history books are written by the victors.
If you want to talk war crimes, let's discuss the fire bombing of Dresden, which had been declared an open city. Or the incendiary raids on Japanese cities in 1944 and 1945, which served no military purpose whatsoever, but were intended to punish and terrify the civilian population, in clear violation of the laws of war.
If the Allies had lost WW2, it would have been Allied generals and politicians on trial at Nuremberg. Because history books are written by the victors.
My point is not to defend National Socialism. My point is that we have been sold a grossly oversimplified version of history, one with white hats and black hats, where the hero gets the girl and rides off into the sunset. History is not like that. All parties involved in WW2 had bloody hands up to their armpits. There were no good guys then, and there are no good guys today. War is a racket.