At a time when the Wehrmacht had just been forced by the Red Army and the Russian winter to move to the defense in the invasion of Russia, Hitler may have wanted to show by declaring war that he was still the master of the situation. Furthermore, throughout his life, Hitler had always gambled and won on the "long shot", betting everything on a single role of the dice. Doing so had served him well up to this point, but his lack of information about the US and his ideological preconceptions about it made this particular choice a very poor one, unlikely to come up in Hitler's favor.