The 'Battle of Dutch Harbor' was fought between Japanese and US forces above Dutch Harbor on Amaknak island in the Aleutian islands group (3/4 June 1942).

The battle began when the Imperial Japanese navy launched the first of two aircraft carrier raids by th 2^nd Carrier Striking Force on the US Navy’s Dutch Harbor Naval Operating Base and US Army’s Fort Mears at Dutch Harbor on Amaknak island, which lies just off the coast of Unalaska island. The Japanese bombing marked the first deliberate air attack by an enemy on the continental USA, the first attack having been the accidental bombing of Naco, Arizona, in 1929.

In the 'Battle of Dutch Harbor', a Japanese aircraft carrier strike force under Rear Admiral Kakuji Kakuta launched air attacks over two days against the Dutch Harbor Naval Base and Fort Mears in Dutch Harbor. The attacks inflicted moderate damage on the US base, and soon after it Northern Force under the command of Vice Admiral Boshiro Hosogaya invaded and occupied Attu and Kiska islands, in 'Aq' and 'Aob' respectively, farther to the south-west in the Aleutian islands chain.

The air raid on Dutch Harbor was undertaken to support the invasions on Kiska and Attu islands by the Japanese in 'Al'. Dutch Harbor was ringed with anti-aircraft artillery batteries of the 206^th Coast Artillery (Anti-Aircraft) Group of the Arkansas National Guard, and was one of key targets protected by Major General William O. Butler’s US 11^th Army Air Force based on the Alaskan mainland. The 206^th CA (AA) had been deployed to Dutch Harbor during August 1941 and had been in this position for about four months when the Imperial Japanese navy air force made it 'Ai' attack on Pearl Harbor in the Hawaiian island group on 7 December 1941. The 206^th CA was equipped with the obsolescent 3-in (76.2-mm) M1918 gun, which had a vertical range of 26,900 ft (8200 m), 0.5-in (12.7-mm) Browning M2 heavy machine guns, and 60-in (1.524-m) Sperry searchlights. The 206^th CA had one radar in position at Dutch Harbor at the time of the attack. In the harbor were the old destroyers King and Talbot, the destroyer/seaplane tender Gillis, the submarine S-27, the US Coast Guard cutter Onondaga and the US Army transport vessels President Fillmore and Morlen. The US Army forces were part of Major General Simon S. Buckner’s US Troops in Alaska command, with Colonel Archibald V. Arnold as the commander of the 44^th Division’s artillery, and the US naval vessels were elements of Rear Admiral Robert A. Theobald’s North Pacific Force (Task Force 8) created for operations in the Aleutian islands group.

At departing Ominata at the northern end of Honshu island in the Japanese home islands on 3 June 1942, Kakuta’s Japanese carrier strike force, comprising the light carriers Ryujo and Junyo, plus escort ships, had reached a point some 180 miles (290 km) to the south-west of Dutch Harbor and readied themselves to launch air attacks on the US Navy and US Army facilities in Dutch Harbor to support the 'Al' offensive in the Aleutian islands group and 'Mi' offensive to take Midway island in the central Pacific. The Japanese planned to occupy islands in the Aleutians in order to extend their defensive perimeter in the North Pacific and thus to make it more difficult for US forces to attack Japan from that area.

At 02.58, shortly before dawn, Kakuta ordered his aircraft carriers to launch their aircraft, which comprised 12 Mitsubishi A6M Reisen 'Zero' single-engined fighters, 10 Nakajima B5N 'Kate' single-engined level bombers and 12 Aichi D3A 'Val' single-engined dive-bombers which took off from the two small carriers in the freezing weather to strike at Dutch Harbor. One B5N was lost on take-off from Ryujo. The Japanese aircraft arrived over Dutch Harbor at 04.07 and attacked the town’s radio station and oil storage tanks, causing some damage. Many members of the 206^th CA were woken by the sound of bombs and gunfire. While the unit had been on alert for an attack for many days, there had been no specific warning of the attack before the Japanese warplanes arrived over Dutch Harbor. With no clear direction from headquarters, gun crews from every battery quickly appreciated the danger, ran to their guns sited round the harbour and began to return fire. In addition to their 3-in (76.2-mm) guns, 37-mm (1.46-in) guns and 0.5-in (12.7-mm) machine guns, members of the unit fired their rifles and one even claimed to have hurled a wrench at a low-flying Japanese aeroplane. Several men reported being able to clearly see the faces of the Japanese pilots and aircrews as the warplanes made repeated runs over the island. The greatest casualties on the first day occurred when bombs struck a pair of barracks in Fort Mears, killing 17 men of the 37^th Infantry and eight of the 151^st Engineers.

When all the Japanese aircraft had been recovered, there were erroneous reports of US ships in the ara, but search aircraft located no US ships. During the search, four Nakajima E8N2 'Dave' single-engined reconnaissance floatplanes, launched from the heavy cruisers Takao and Maya met US fighters now searching for the departing Japanese squadron.

The 206^th CA spent much of the night of 3/4 June moving its guns off the mountain tops surrounding the harbour down into the town of Unalaska and into harbour facilities themselves. This was in part as a deception and in partial to defend against an expected land invasion. Civilian contractors offered to help and were put to work filling sandbags to protect the new gun positions.

On 4 June, the Japanese carriers steamed to a position less than 100 miles (160 km) south of Dutch Harbor to launch a second attack. At 16.00, a second attack wave, comprising nine fighters, 11 dive-bombers and six level bombers, took off and attacked the US facilities once more less than one hour later. More targets were damaged, these including some grounded aircraft, an army barracks, oil storage tanks, aircraft hangars, and a few merchant ships in the port. During this attack, the A6M fighters concentrated on strafing the gun positions while their level bombers and dive-bombers destroyed the fuel tanks in the harbour area. One wing of the base’s military hospital was also destroyed. After hitting the fuel tanks, the dive-bombers and level bombers concentrated their efforts on Fillmore and Gillis. 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. Northwestern was in reality a transport ship which had been beached and became used as a barracks for civilian workers. Although the ship was badly damaged and left in flames, firefighters managed to save the hull, and its power plant was thereafter used to produce steam and electricity for the shore installations. One anti-aircraft gun was blown up by a bomb and four US Navy personnel were killed.

Two Japanese dive-bombers and one fighter, damaged by anti-aircraft fire, failed to return to their carriers. On their flights way back to the carriers, the Japanese aircraft encountered a patrol of six Curtiss P-40 single-engined fighters over Otter Point, and in the short aerial battle which ensued one Japanese fighter and two more dive-bombers were shot down. Two out of the six US fighters were also lost.

As a result of the Japanese attacks, the 11^th AAF lost four Boeing B-17 Flying Fortress four-engined heavy bombers, two Martin B-26 Marauder twin-engined medium bombers and two P-40 fighters, while the US Navy suffered the more with six Consolidated PBY twin-engined flying boats destroyed. Some 43 Americans were killed, these being 33 soldiers, eight sailors, one marine and one civilian. Another 50 were wounded in the attack.[11]

None of the Japanese ships was damaged, but one of the A6M fighters mentioned above, an A6M2 machine, was damaged by ground fire and crash-landed on Akutan island, about 20 miles (32 km) to the north-east of Dutch Harbor. Although the pilot was killed, the aeroplane was not seriously damaged. This aeroplane, known as the 'Akutan Zero' was recovered by US forces, inspected, repaired and test flown. The recovery was an important technical intelligence gain for the USA as it revealed the strengths and weaknesses of the A6M’s design.

On the following day, Kakuta received orders to break off the attacks of his and head for the central Pacific to support Admiral Isoroku Yamamoto’s Combined Fleet which was retreating after heavily defeated in the 'Battle of Midway' that resulted from 'Mi'. Two days later, a small Japanese invasion force landed and occupied two of the Aleutian islands, Attu and Kiska, without further incident.

The Japanese bombing of Dutch Harbor and their subsequent occupations of Kiska and Attu helped to trigger an impression among Americans that the Japanese planned to launch a full-scale attack along the USA’s west coast. As a result, military and commandeered civilian aircraft flew nearly 2,300 troops to Nome in Alaska, along with artillery, anti-aircraft guns and several tons of other equipment and supplies in an effort to deter a possible Japanese landing on mainland Alaska.

Fearing a Japanese attack on other islands of the Aleutian group and on the Alaskan mainland, the US government evacuated hundreds more Aleuts from the western chain and the Pribilof islands group, locating them in internment camps in south-eastern Alaska, where many died of measles, influenza and other infectious diseases which spread quickly in the overcrowded dormitories. In total, about 75 islanders died in US internment and 19 as a result of Japanese occupation. The Aleut Restitution Act of 1988 was an attempt by the Congress to compensate the survivors, and on 17 June 2017, the US government formally apologised for the internment of the Unangan people and their treatment in the camps. Aleuts on Kiska and Attu were imprisoned on the Japanese main islands.