Declaring war on the United States
When Franklin Roosevelt asked for a declaration of war against Japan the day following the attack on Pearl Harbor he made no mention of Hitler, Germany, or the war in Europe. Although the United States was already involved in combat operations against German U-Boats, following a standing order to “shoot on sight”, Roosevelt’s speech was focused on the Japanese attacks in the Pacific. American and British military planners had already established, in prewar (for the United States) conferences, that the strategy to be followed when the United States entered the war was the destruction of Germany first, and that European operations would take priority over actions against Japan.
On December 11, 1941, Adolf Hitler declared war on the United States, the single biggest mistake made by the Axis, and by Hitler himself, during World War II. Although Japan had disregarded the Tripartite Pact as it applied to the Russo-German war, its ambassador requested of Joachim Ribbentrop that Germany declare war against the United States. Hitler made the decision to declare war after learning of the Japanese attack on Singapore, and that Britain had joined in the war against Japan. It was a decision, which according to John Kenneth Galbraith, one of Roosevelt’s advisors, was unwise. “It was a totally irrational thing for him to do,” wrote Galbraith, continuing, “and I think it saved Europe.”