The establishment of the U.S. as a global superpower was significantly marked by its victory in World War II. Entering the war in 1941 after the attack on Pearl Harbor, the U.S. mobilized its vast resources and industrial capacity to support the Allied forces. The post-war period saw the U.S. emerge economically strengthened, with a leading role in international politics, particularly through the creation of the United Nations and the Marshall Plan. This newfound status was underscored by its nuclear capability and involvement in global affairs, positioning the U.S. as a dominant force that shaped international relations for decades to come.