Module 7: Pearl Harbor and American Entry into WWII

Pearl Harbor and American Entry into the War

American entry into World War II was catalyzed by a series of escalating tensions and aggressive actions by Japan, culminating in the infamous sneak attack on Pearl Harbor on December 7, 1941. Prior to this, President Franklin D. Roosevelt (FDR) had been increasingly concerned about Japanese expansion in Asia, particularly in Indochina and the Pacific. In response, the United States imposed economic sanctions on Japan, including an embargo on oil, which was critical to its military operations. These sanctions aimed to curb Japanese aggression, but instead, they pushed Japan towards further military action as it sought to secure vital resources in Southeast Asia.

The attack on Pearl Harbor was devastating, resulting in the loss of numerous ships, aircraft, and thousands of American lives. It galvanized public opinion in the United States, shifting from isolationism to overwhelming support for entering the war. The day after the attack, FDR delivered his famous "Day of Infamy" speech, calling for a declaration of war against Japan. The assault on Pearl Harbor not only targeted the U.S. Pacific Fleet but also set in motion a broader conflict across the Pacific, as Japan launched simultaneous attacks on American-held territories, including the Philippines, Guam, Wake Island, and further into Malaya and Singapore.

In the wake of Pearl Harbor, the United States found itself fully committed to the war effort, uniting the nation under a common cause. The loss at Pearl Harbor, however, also served as a wake-up call, highlighting the need for increased military preparedness and coordination. American forces quickly mobilized to respond to Japanese advances throughout the Pacific, leading to a series of campaigns aimed at reclaiming lost territory and countering Japanese aggression. The attack not only marked the United States’ entry into World War II but also reshaped the dynamics of the conflict, setting the stage for a protracted and intense struggle in the Pacific Theater.