Documentary Review: Great Blunders of WWII: Hitlers's Declaration of War on the United States

Adolf Hitler was persuaded by Japan to declare war on the United States after Pearl Harbor.  However there was no reason to have done so according to treaty.  The Germans has pledged to defend Japan if Japan were attacked.  That was not the case here.  However Hitler was quick to declare war against the United States.  Perhaps Hitler was hoping Japan would tie the Soviets down in the West.  This did not happen.  By doing so, United States entered the war in Europe.  Winston Churchill had been negotiating for this for some time, as England could not win the war on her own.  Hitler  with his declaration resolved this problem for Churchill.  The United States put is industrial might, as well as armed forces to defeating Germany and Japan.