The short answer: Not much would have been different.
The long answer: possible significant difference, but only if OTHER radically different decisions had also been made afterward to build on that decision.
Hitler wanted to do like Napoleon and wage his European war with the US staying the hell out of it.
So his decision to declare war on the US on the heels of Pearl harbor seems irrational. But Hitler knew that his war with the UK demanded cuting off the UK supply lines across the Atlantic. Much of that supply line came from the US and came in US cargo ships. And the US already had small warships helping to guard convoys. American sailors had already died on the Destroyer Reuben James in the Battle of the Atlantic even BEFORE Pearl Harbor (Americans had already died fighting Hitler even before Pearl Harbor). Hitler didnt like it, but he realized that he needed license to let his Uboats attack American shipping. And he knew that the best time to kick the US Navy was when the US Navy was already down from Pearl Harbor. So he declared war. And it was probably the best possible decison for his interests given the circumstances.
If he had not done that then in theory the US would have been at war with Japan, but not also with Germany. But Britain would have been at war with Germany, AND with Japan. So the US would have been allies with Britain against Japan but not against Germany. But the US would have kept on supplying Britain by sea. American ships would have been accidently , or purposely targeted by U boats. More and more incidents like Reuben James would have occured, and soon either FDR, or Hitler, would have declared war on the other. Its hard for me to imagine how Britain and Germany could have kept on waging the Battle of the Atlantic without drawing the US in on the side of Britain. So Hitler not declaring war on the US on December eleventh only would have delayed things by weeks or a couple months. It would have been essentially the same World War Two that we had.
However: one could imagine this. The Japanese attack Pearl Harbor and then Hitler unexpectadly responds by extending an olive branch to Britain. Hitler had already conquered most of mainland Europe, and was waging war in Russia. Hitler concievabley could have persuaded the UK to accept a seperate peace (and kept on fighting Russia). Told Churchill "we wont try to conquer the British Isles if you Brits dont try to liberate Europe, and we Germans will take Romel out of North Africa and break off attacking Egypt. Hows that for a deal? "The Brits MIGHT have gone for it. So you would have had Germany and Russia still fighing, and the US and Japan fighting, but Britain suddenly neutral against Germany. But British Empire territories were attacked by Japan at the same time or shortly after the Japanese attack on Pearl Harbor. So Britain and the US would have ganged up on Japan, but not against Germany.
So you would have had Germany at war in Russia. And the Britain and the US fighting Japan in the Pacific and east Asia. But an uneasy ceasefire in the Atlantic Ocean and in western Europe between Germany and Britain.
So the combination of Hitler not declaring war on Dec. 11 with Hitler also making a seperate peace with the UK might have changed the way the war went at least in the short run. Hard to say.It would have taken a lot of effort by Germany (on one hand), and by Britain and the US (on the other) to not descend back into fighting each other in the long run though.
05 Mar 2018, 6:32 pm
