Pearl Harbor attack

Table of Contents

References & Edit History Quick Facts & Related Topics

Images & Videos

Pacific War: Japanese-controlled areas of China

Examine the facts and timeline of the attack on Pearl Harbor on December 7, 1941

Learn why Japan attacked Pearl Harbor causing the United States to join Allied forces in World War II

Watch Japanese dive-bombers attack the U.S. naval base at Pearl Harbor to spark the Pacific War

For Students

Germany invades Poland, September 1, 1939, using 45 German divisions and aerial attack. By September 20, only Warsaw held out, but final surrender came on September 29.

Pop Quiz: 17 Things to Know About World War II

Pearl Harbor attack summary

Pearl Harbor attack

Q: Why did Japan attack Pearl Harbor?

By mid-1941 the United States had severed all economic relations with Japan and was providing material and financial support to China. Japan had been at war with China since 1937, and the German invasion of the Soviet Union in June 1941 ensured that the Soviets were no longer a threat to the Japanese on the Asian mainland. The Japanese believed that once the U.S. Pacific Fleet was neutralized, all of Southeast Asia would be open for conquest.

Q: How long did the Pearl Harbor attack last?

The first Japanese dive-bomber appeared over Pearl Harbor at 7:55 AM (local time) on December 7, 1941. Over the next half hour, Pearl Harbor’s airfields and docked ships were subjected to a merciless assault with bombs, guns, and torpedoes. A second wave struck at 8:50 AM, and the Japanese withdrew shortly after 9:00 AM. In just over an hour, the Japanese destroyed more than 180 aircraft and destroyed or damaged more than a dozen ships. More than 2,400 U.S. military members and civilians were killed. Learn more in this infographic.

Q: Was the Pearl Harbor attack successful?

In the short term, the American naval presence in the Pacific was severely weakened. However, the Japanese had largely ignored the harbour’s infrastructure, and many of the damaged ships were repaired on-site and returned to duty. In addition, the Pacific Fleet’s three aircraft carriers were not present at Pearl Harbor (one had been scheduled to return the day before the attack, but it was delayed by bad weather). American opinion immediately shifted to favouring war with Japan, a course that would conclude with Japan’s unconditional surrender less than four years later.

Q: Did the Pearl Harbor attack signal the beginning of World War II for the United States?

The Japanese attack on Pearl Harbor marked the beginning of the Pacific war for the U.S., but it did not necessarily mean that the U.S. had become a combatant in the war in Europe. By December 1941, German armies had stalled on the Eastern Front, and it seemed foolhardy for Adolf Hitler to declare war on yet another great power under such circumstances. The Tripartite Pact only obligated Germany to defend Japan if the latter was attacked, not if it was the aggressor. Nevertheless, Germany declared war on the United States on December 11, 1941. Later that month, British Prime Minister Winston Churchill met U.S. Pres. Franklin Roosevelt at the Arcadia Conference in Washington, D.C., and the two agreed on a “Europe first” policy for the defeat of Nazi Germany .

Q: What is Pearl Harbor like today?

Pearl Harbor is a U.S. Navy base on the Hawaiian island of Oahu and the headquarters of the U.S. Pacific Fleet. Adjacent to the harbour is Hickam Air Force Base, and the two installations were merged in 2010 to become Joint Base Pearl Harbor–Hickam. The USS Arizona remains where it sank on December 7, 1941, and it is preserved as a national cemetery. The USS Arizona Memorial is one of the most visited tourist attractions in Hawaii.

Japanese-United States history

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Mar 8, 2024 • Article History

Pearl Harbor attack

See all media

Category: History & Society

Date:: December 7, 1941

Location:: Hawaii; Oahu; United States

Participants:: Japan; United States

Context:: Operation Barbarossa; Pacific War; Second Sino-Japanese War; World War II

Key People:: Nagano Osami; Tōjō Hideki; Yamamoto Isoroku; Husband Edward Kimmel; Walter Campbell Short

See all related content →

Recent News

Mar. 7, 2024, 5:34 PM ET (MSN)

Remains of Navy sailor killed in Pearl Harbor attack identified

Why did Japan attack Pearl Harbor?

How long did the Pearl Harbor attack last?

Was the Pearl Harbor attack successful?

Did the Pearl Harbor attack signal the beginning of World War II for the United States?

What is Pearl Harbor like today?

Pearl Harbor attack, (December 7, 1941), surprise aerial attack on the U.S. naval base at Pearl Harbor on Oahu Island, Hawaii, by the Japanese that precipitated the entry of the United States into World War II. The strike climaxed a decade of worsening relations between the United States and Japan. In the late 1930s, American foreign policy in the Pacific hinged on support for China, and aggression against China by Japan therefore necessarily would bring Japan into conflict with the United States. As early as 1931 the Tokyo government had extended its control over the Chinese province of Manchuria, and ...(100 of 3286 words)

Access the full article

Help support true facts by becoming a member.