Archives, U.S. Government c. 1942-43.
In June 1942, during the Battle of Midway, a Japanese carrier force staged a diversionary attack on Dutch Harbor. American aircraft carriers, however, were not diverted from Midway where they obtained a decisive U.S. naval victory.
Unopposed Japanese forces then occupied Agattu, Kiska and Attu islands.
Although fierce Arctic storms and fog around the islands made any attempt to use the Aleutians as a bridge to the Alaskan coast difficult, occupation of the western Aleutians brought several theoretical advantages to Japan: the possibility of a gradual incursion onto the North American continent, a threat to vital shipping lanes between the Pacific Northwest and the USSR, and protection of the airspace over the home islands of Japan from U.S. bombing.
Shortly after landing, the Japanese withdrew from Agattu and began building airstrips on Kiska.
American troops built air bases on the island of Adak about 210 miles east of Kiska, and occupied the island of Amchitka about 60 miles east of Kiska.
While public opinion in the USA was strongly in favor of retaking the Aleutians as soon as possible, operations in the Central Pacific were of higher priority and American efforts to recapture Kiska and Attu would not develop for months.