On Dec. 7, 1941, Japan launched an aerial attack on a U.S. Naval base in Pearl Harbor, Hawaii, killing over 2,000 Americans. The following day, the U.S. declared war on Japan, beginning its involvement in World War II.
The Attack on Pearl Harbor
In September 1940, following the defeat of France and the evacuation of most British troops from continental Europe, Japan aligned itself with Germany and Italy, becoming the third element in the tripartite alliance of Axis Powers.
Japanese-U.S. relations worsened, and America imposed economic sanctions on Tokyo in response to its occupation of Manchuria and war against China. Japanese imperial forces sought to expand their military and economic domination of Asia. To do that with impunity, Tokyo sought to cripple America’s naval presence in the Pacific.
Japan attempted to send out a last minute declaration of war to “avoid a charge of ‘attack without warning,’ but the plan cut the time element too fine,” writes the U.S. Army Center of Military History. U.S. forces had not received warning by the time the first wave of Japanese planes attacked Pearl Harbor soon before 8 a.m. A second wave followed an hour later.
Torpedoes and high-explosive and incendiary devices sank or damaged 21 vessels of the U.S. Pacific Fleet and destroyed 188 aircraft within two hours. U.S. casualties numbered in the thousands; some 1,177 American servicemen died on board the battleship Arizona, which for many became their final resting place and a continuing memorial.
The American Response
Sources in this Story
- U.S. Army Center of Military History: Guarding the United States and Its Outposts: The Pearl Harbor Attack
- Naval Historical Center: The Pearl Harbor Attack, 7 December 1941
- American Rhetoric: Franklin Delano Roosevelt: Pearl Harbor Address to the Nation
- Time: National Ordeal
- PBS: The Perilous Fight: Pearl Harbor
- The USS Enterprise CV-6 Association: The Doolittle Raid
- The War Times Journal: The Pacific War Series
The next day, in one of the most famous congressional addresses from a president, Franklin D. Roosevelt called Dec. 7, 1941, “a date which will live in infamy.” Congress formally declared war on the Japanese Empire just hours later.
“The Nation had taken a heavy blow. The casualties crept from rumor into uglier-rumor: hundreds on hundreds of Americans had died bomb-quick, or were dying, bed-slow,” wrote Time magazine. “But the war came as a great relief, like a reverse earthquake, that in one terrible jerk shook everything disjointed, distorted, askew back into place. Japanese bombs had finally brought national unity to the U.S.”
According to legend, Japanese Adm. Isoroku Yamamoto remarked, “I fear we will awaken a sleeping giant.” The U.S. fought Japan—and Nazi Germany and Italy, who declared war on Dec. 11—for the next four years, achieving victory in August 1945.
Photo Galleries of the Attack
View photos of the Pearl Harbor attack and its aftermath from Life Magazine and the U.S. Naval History and Heritage Command.
Witness and Response Accounts
The U.S. Naval History and Heritage Command provides reports of the attack filed by commanding officers and other survivors at Pearl Harbor, as well as a teachers guide for using the accounts in class.
EyeWitness to History offers eyewitness accounts from U.S. Marine Cpl. E.C. Nightingale, who was aboard the USS Arizona, and Japanese Commander Mitsuo Fuchida, who led the first wave of attacks.
The Library of Congress holds 12 hours of “man-on-the-street” interviews conducted across the country in the days following the Pearl Harbor attack.
Historical Context: The Pacific War
Related Events
- Bombing of Chongqing
- Japanese Submarine Attacks on Oregon
- Japanese “Balloon Bomb” Campaign
- Japanese Kamikaze Attacks
- Internment of Japanese-Americans
The U.S. launched a retaliatory attack in April 1942, when Lt. Col. James H. Doolittle led a bombing mission on Tokyo. The “Doolittle Raid” had little strategic impact, but it was “a tremendous boost to American morale, which had been severely tested by four long months of defeat and loss.”
Fighting in the Pacific Theater continued for another three years, with the U.S. and the Allied powers winning important battles at Midway, Guadalcanal and elsewhere. By 1945, Japan was losing battles on its home islands of Iwo Jima and Okinawa and its mainland was under attack from U.S. B-29 bombing missions.
In August 1945, the U.S. dropped atomic bombs on Hiroshima and Nagasaki, devastating Japanese resistance. On Aug. 15, Japan officially surrendered, ending World War II.
