High Quality Content by WIKIPEDIA articles! The Battle of Attu, which took place from 11-30 May 1943, was fought entirely between forces of the United States and the Empire of Japan on Attu Island off the coast of Alaska. The action, which was 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 battle in which Japanese and American forces fought in Arctic conditions.