Only four days after the December 7, 1941 Japanese attack on Pearl Harbor, the United States (which had managed to remain more or less neutral as the conflicts of WWII spread across Europe and parts of Asia) found itself pitted against yet another Axis power – Germany. Hitler had decided to take action against the United States.
On December 11, 1941, in front of a packed theater of his Reichstag peers (members of the German state legislature), Hitler delivered the speech that would change the course of WWII and solidify Germany's eventual defeat. By choosing to pursue aggressions with the United States, Hitler ensured a continued alliance between Britain and the US, severely underestimating the extent to which the United States was militarily and industrially prepared to fight overseas.
Hitler's decision has been viewed as rash and ill advised, and it has even been attributed to his coming out of hurt ego, which got bruised when his Japanese allies went after the US without consulting him and he wanted to regain an upper hand in the strategically delicate relationship. Regardless of his reasoning, Hitler's speech that afternoon was one of impassioned rhetoric and devastating consequences for the future of the Third Reich.
Even before the Japanese attacked the US, Hitler had already begun drafting up plans for how to bait the country into reacting aggressively. Because of the ideological conflicts between him and President Roosevelt, Hitler felt that a conflict with the Western superpower was not only inevitable, but also necessary.
Hitler even openly criticized the President for his New Deal program, accusing Roosevelt of attempting to cover up his extreme economic failures with attempts at misguided social reform. "First he incites war, then falsifies the causes, then odiously wraps himself in a cloak of Christian hypocrisy and slowly but surely leads mankind to war,” Hitler announced.
While Hitler was trying to craft a plan that would force the US to become involved in the global conflict, Japan was one step ahead. Taking Hitler's advice to "strike – as hard as possible – and not waste time declaring war," Japan suddenly and unpredictably attacked the US at Pearl Harbor on December 7, 1941. This surprised not only the US, but also the Führer himself.
Hitler, who had not been informed of Japan's plan despite their close strategic relationship, was relieved to have a clear path set out before him. And with the establishment of the Tripartite Pact – which declared that Germany would come to Japan's aid in the event of an attack – Hitler saw this as an opportunity to both prove Germany's solidarity with Japan and further strengthen the political and strategic bonds of the Axis powers.
Hitler, in more ways than one, believed that it was his destiny to become a historically renowned world leader, and, by adding the US to his graveyard of defeated powers, he would attain his goal all the more quickly. During his declaration, Hitler revealed just a sliver of his over-inflated self image, stating:
"I can only be grateful to Providence that it entrusted me with the leadership in this historic struggle which, for the next five hundred or a thousand years, will be described as decisive, not only for the history of Germany, but for the whole of Europe and indeed the whole world."
However, in his rose-colored vision of a world dominated by Hitler's regime, he mistakenly underestimated the extent of the US's military power and made what historians (and even his own contemporaries) believe to have been his greatest mistake.
Germany, which was already locked in combat with the Soviet Union and Great Britain, as well as in the midst of enacting a massive destructive mission across Europe, had spread its military remarkably thin with very few triumphs to account for. In fact, German Foreign Minister von Ribbentrop warned Hitler against the action, pointing out that Germany needed first to regain its numbers and secure its various battlefronts before instigating yet another. But temptation was too great for Hitler, and he carried out his declaration anyway, pushing the US to join with the Allies and ensuring the downfall of the Axis powers.