Though a complete list of Hitler’s blunders would be too long for any history blog, even this one, today in history, 69 years ago, Hitler made a serious blunder by declaring war against the United States shortly after the attack on Pearl Harbor by Nazi Germany’s ally, Japan.  Apparently, Hitler did not know in advance about the Japanese sneak attack, but decided to show solidarity with its ally in the Pacific and make a preemptive declaration of war on the US itself.

At this point in time, it is somewhat unclear why this was done, though there are at least a couple of reasons that would make some sense.  For one, the United States and Germany were already involved in a quasi war over convoying in the Atlantic, and attacks on America’s “neutral” shipping are one of the most reliable ways of provoking warfare with the United States (see the War of 1812 and World War I).  Before Pearl Harbor, it was unknown which nation of the Axis the United States would be at war with first.

The other sensible reason why Germany declared war on the United States was in support of its ally.  This reason makes a little less sense, as Germany was not always quick to declare war on behalf of its allies.  For example, Finland had to face the wrath of the Soviet Union alone in the Winter War of 1939-1940, and did a good job, if suffering defeat because of overwhelming Soviet numbers.  Likewise, Italy’s warfare against Albania and then Greece were done on its own, because Mussolini sought glory for the Italian military and defeating Albanians and Ethiopians apparently didn’t help that cause very much.

Nonetheless, in June of 1941, Hitler invaded the Soviet Union, and by December his attacks on Moscow were getting bogged down by the Russian winter and the energetic defense of Marshal Zhukov.  Japan and the Soviet Union had engaged in some battles along the borders of Manchuria in 1939-40 (where the Soviets were again led by Zhukov–this fellow was busy) and Japan came off decidedly the worst, and so a truce was set between the two sides.  Perhaps Hitler was looking for a quid pro quo–I’ll declare war on your mortal enemy (the United States) in the hope that you will declare war on mine (the Soviet Union).  If that was Hitler’s intention, the gambit failed.

The declaration of the war on the United was a massive blunder for one particular reason.  The United States, like the Roman Empire, is very fussy about the legalistic forms of its declarations of war, more fussy than most nations on earth.  Given the strong support for Nazi Germany and isolationism within strong elements of American society (including Henry Ford, for example), it is likely that had the United States been forced to declare war on Germany first it would have been a much more divisive process, similar to the divisions that took place over America’s involvement in the First World War.  However, by declaring war on the United States, all that was necessary for the United States to do was respond in kind–no divisive argument over war declaration had to take place, and Roosevelt was able to support his ally in Great Britain without having to convince the American people to support a declaration of War on Nazi Germany.  By doing Roosevelt’s work for him, Hitler made a serious blunder today in 1941.