During World War II, the civilian population was evacuated to the Japanese home islands and Simushir was garrisoned by a detachment from the Imperial Japanese Army. It was surrendered to Soviet forces during the Battle of the Kuril Islands without resistance.
During World War II, civilian populations were evacuated to the Japanese home islands, and Simushir was held by a military unit from the Imperial Japanese Army. The island was captured by Soviet forces during the Battle of the Kuril Islands with no opposition.