The Battle of Attu Island which took place from May 11–30, 1943, was fought entirely between forces of the United States and the Empire of Japan on Attu Island off the coast as part of the Aleutian Islands Campaign during the Pacific War, was the only land battle of World War II fought on territory that was part of the incorporated territory of the U.S. It is also the only land battle in which Japanese and American forces fought in Arctic conditions.
The battle, which lasted for more than two weeks, ended when most of the Japanese defenders were killed in brutal hand-to-hand combat after a final banzai charge broke through American lines.
The strategic position of the islands of Attu and Kiska meant their location could control the sea lanes across the Northern Pacific Ocean.
Japanese planners believed control of the Aleutians would therefore prevent any possible U.S. attacks from Alaska. This assessment had already been inferred by U.S. General Billy Mitchell who told the U.S. Congress in 1935, "I believe that in the future, whoever holds Alaska will hold the world.
I think it is the most important strategic place in the world." On June 7, 1942, six months after the United States entered World War II, the 301st Independent Infantry Battalion from the Japanese Northern Army landed unopposed on Attu. The landings occurred one day after the invasion of nearby Kiska. The U.S military now feared both islands could be turned into strategic Japanese airbases from which aerial attacks could be launched against the West Coast of North America.
In Walt Disney′s 1943 film Victory Through Air Power, the use of the Aleutian Islands for American long-range bombers to bomb Japan from American territory was postulated.[
In May 1943, units from 17th Infantry, of the U.S. 7th Infantry Division made amphibious landings on Attu to retake the island from Japanese Imperial Army forces led by Colonel Yasuyo Yamasaki.
Despite heavy naval bombardments of Japanese positions, the American troops encountered strong entrenched defenses that made combat conditions tough. Arctic weather conditions and exposure-related injuries also caused numerous casualties among U.S. forces. But after two weeks of relentless fighting, American units managed to push the Japanese defenders back to a pocket around Chichagof Harbor.
On May 29, without hope of rescue, Yamasaki led his remaining troops in a banzai charge. The momentum of the surprise attack broke through the American front line positions.
Shocked American rear-echelon troops were soon fighting hand-to-hand combat with Japanese soldiers. The battle continued until almost all of the Japanese were killed.
The charge effectively ended the battle for the island, although U.S. Navy reports indicate that small groups of Japanese continued to fight until early July. In 19 days of battle, 549 soldiers of the 7th Division were killed and more than 1,000 injured. The Japanese lost over 2,850 men; only 29 prisoners were taken alive.
Attu was to be the last action of the Aleutian campaign. The Japanese Northern Army secretly evacuated their remaining garrison from nearby Kiska, ending the Japanese occupation in the Aleutian Islands on July 28, 1943.
The loss of Attu and the evacuation of Kiska came shortly after the death of Admiral Isoroku Yamamoto, who was killed by an American plane in Operation Vengeance.
These defeats compounded the demoralizing effect of losing Yamamoto on the Japanese High Command. Despite the losses, Japanese propaganda attempted to present the Aleutian Island campaign as an inspirational epic.