After all, the US was involved in a major war with Japan, which had commenced with a major defeat. No doubt FDR would have liked to fight Hitler. But the fact that he had not declared war years ago made it plain he did not have the necessary political support.

Of course the US could have declared war on Germany at any time. But Germany lacked the power to undertake any serious attacks on the US. So there was nothing to lose by gambling that FDR would have even less support for entering the European war after Pearl Harbour. This was a situation where the most sensible thing Hitler could do was nothing.

Remember the situation. England & France had declared war on Germany the previous year in 1939 — although they had then sat on their hands and done nothing much to make actual war on Germany. This was the now often-ignored nearly year-long Phony War.

How could Germany attack east to the USSR when it had self-declared belligerents at its back on its western border? It probably seemed like a rational decision from Germany’s perspective to take out those apparently-incapable declared enemies on the west before attacking its nominal ally on the east.

One of many unanswerable questions is what Germany would have done if those virtue-signaling English & French had not declared war on Germany? Ex-President Hoover’s assessment was that Germany really intended to focus on the USSR; England & France had foolishly interrupted that plan.

Japan was an ass for attacking the US before seizing what it wanted from the USSR first. Japan wanted a lot from the USSR and was stupid for its choices.