The Japanese planned to occupy islands in the Aleutians in order to extend their defensive perimeter in the North Pacific to make it more difficult for the U.S. to attack Japan from that area.

The air raid on Dutch Harbor was conducted to support the invasions on Kiska Island and Attu Island by the Japanese military under Operation AL. Dutch Harbor was ringed with anti-aircraft artillery batteries from the 206th Coast Artillery (Anti Aircraft) group of the Arkansas National Guard, and was one of the key targets protected by the Eleventh Air Force based out of mainland Alaska.

In the harbor were two old destroyers, King and Talbot, destroyer-seaplane tender Gillis, submarine S-27, Coast Guard cutter Onondaga, and U.S. Army transports President Fillmore and Morlen.

[4] On 3 June 1942 a Japanese carrier strike force, under the command of Rear Admiral Kakuji Kakuta, comprising the carriers Ryūjō and Jun'yō plus escort ships, sailed to 180 mi (160 nmi; 290 km) southwest of Dutch Harbor to launch air strikes at the United States Army and United States Navy facility to support a Japanese offensive in the Aleutians and in the central Pacific at Midway.

[5] The highest casualties on the first day occurred when bombs struck barracks 864 and 866 in Fort Mears, killing 17 servicemen of the 37th Infantry and eight from the 151st Engineers.

Driven away from these two targets by intense anti-aircraft fire, they finally succeeded in destroying the station ship Northwestern which, because of its large size, they mistakenly believed was a warship.

As a result of the enemy actions, the Eleventh Air Force lost four B-17s, two Martin B-26 Marauders, and two P-40s, while the Navy suffered six PBY Catalinas destroyed.

[10] None of the Japanese ships were harmed, but one Zero was damaged by ground fire and crash-landed on Akutan Island, about 20 mi (17 nmi; 32 km) northeast of Dutch Harbor.

[11] The following day, Admiral Kakuta received orders to break off further attacks and head for the central Pacific to support the Combined Fleet which was retreating after being defeated at Midway.

The bombing of Dutch Harbor and the subsequent occupations of Kiska and Attu by the Japanese helped trigger an impression among Americans that they were going to launch a full-scale attack along the United States West Coast.

As a result, military and commandeered civilian aircraft flew nearly 2,300 troops to Nome, along with artillery and antiaircraft guns and several tons of other equipment and supplies to deter a possible Japanese landing in mainland Alaska.