With the entry of the United States into the war following the Japanese attack on Pearl Harbour, the Canadian Government of Prime Minister Mackenzie King offered military naval and air support to the then limited American capabilities facing Japanese expansion in the Aleutian Islands. Two fighter and light bomber wings were formed for service on the Pacific coast, X and Y Wings composed of Kittyhawk fighters and Bolinbroke light bombers under the RCAF Western Air Command. 118 Sqn would join 115 Sqn forming Y Wing.