Given Germany's increasingly precarious position in the Soviet Union, diverting any resources away from the Eastern Front made little sense.
Pearl Harbor signified the American entry into World War II via the Pacific theatre. Moreover, only days after the attack, Hitler declared war on the United States, thereby involving the US in the European conflict. Similar to his decision regarding Dunkirk, the logic behind Hitler's reasoning here is unclear. Given Germany's increasingly precarious position in the Soviet Union, diverting any resources away from the Eastern Front made little sense. However, some speculate that Hitler had planned for some sort of military engagement with the United States for years. Therefore, after Pearl Harbor, he may have thought that the Americans would be weak, making then an optimal time to initiate a conflict. No matter the reasoning, the United States was now involved in both the European and Pacific wars.