To be brutally precise, Yvonne, the US entered the war because Hitler declared war on the US. One show of Axis hubris too many, because it certainly tipped the balance against them. But the Allies would still have lost before the US got the chance to drop Herr von Braun's bombs, but for the Soviet Union seeing off some 170 Wehrmacht divisions, numbering several million troops. (Sorry to drift from the content, if not the title, of the thread.)