[3] In addition, the air raid on Minami-Tori-shima by the United States in March 1942 raised concerns about the North Pacific Ocean throughout the Japanese military.

The Imperial Japanese Army was reluctant to occupy the Aleutian Islands and responded to the navy on 16 April that they would not dispatch troops to the operation.

[7] In other words, the purpose of Operation AL was to build a patrol network in the North Pacific by establishing bases on Midway, Attu, and Kiska to monitor attacks on Japan mainland by US task forces.

The army established the North Sea Detachment (Hokkai-shitai) on 5 May, headed by Major Matsutoshi Hozumi and consisting of approximately 1,000 men.

[9] Hozumi was tasked to secure or destroy key points in the western part of the Aleutian Islands, and to make enemy mobility and air power advance in this area difficult.

Initially, the only American military presence on Kiska was a 12-man United States Navy weather station—two of whom were not present during the invasion—and a dog named Explosion.

The search ended in vain, with House surrendering some 50 days after the initial seizure of the weather station, having been unable to cope with the freezing conditions and starvation.

On 6 February 1942, the construction of the Alaska Highway was approved by the US Army and the project received the authorization from Congress and President Franklin D. Roosevelt to proceed five days later.

On July 29, 1943, Rear Admiral Kimura Masatomi, commanding two light cruisers and ten destroyers, slipped through the American blockade under the cover of fog and rescued 5,193 men.

[12] The successful evacuation of the garrison was subject of 1965 Seiji Maruyama's movie "Taiheiyô kiseki no sakusen: Kisuka" (literally, "Miracle Operation in the Pacific: Kiska").

Grunion was lost a few weeks later off Kiska on 30 July with all hands; she is suspected of being sunk after one of her own torpedoes circled back when she attacked the Kano Maru.