The attack on Dutch Harbor

Early on the morning of 3 June 1942 aircraft from two Japanese carriers appeared over the US Navy base at Dutch Harbor on Unalaska island, in the Aleutian chain. The raid was repeated the following afternoon. It was the first air attack of the war on United States territory in North America and at the same time the beginning of the Aleutian campaign, which was to last fourteen months. On the same day, far to the south in the central Pacific, American aircraft from Midway first sighted the Japanese invasion force, and the Battle of Midway began; both operations were parts of a single Japanese plan.

The dates require one caveat. Dutch Harbor lies east of the International Date Line, and Japanese documents kept time by Tokyo. Japanese studies therefore place the first raid on 4 June and the second on 5 June. Local dates are used throughout, as in most American and European studies.

Operation AL

Admiral Isoroku Yamamoto’s plan provided for two parallel operations. Under the code name MI, the main forces of the Combined Fleet were to seize Midway Atoll and destroy the American carriers when they came out to defend it. Under the code name AL, Vice Admiral Boshirō Hosogaya’s Northern Force was to bomb Dutch Harbor, destroy military installations on Adak island and occupy the two westernmost islands of the archipelago, Kiska and Attu. Preparations for both operations went ahead in parallel, and the forces assigned to the Aleutians sailed from Ōminato, at the northern tip of Honshū, at the end of May.

For decades Operation AL was presented as a diversion intended to draw the American fleet north. More recent research based on Japanese documents, especially the work of Jonathan Parshall and Anthony Tully, rather shows an operation with objectives of its own. From the beginning of 1942 the navy had feared American carrier raids from the northern Pacific, and the Doolittle Raid of 18 April confirmed those fears; only after it did the army agree to provide troops to occupy the islands. Japanese bases in the western Aleutians were to push the patrol line further east, bar the Americans’ route from Alaska towards the Kuril Islands and hamper any air co-operation between the United States and the Soviet Union. Some Japanese planners also reckoned that an attack on American territory would additionally force the Americans to put to sea. The attack on Dutch Harbor preceded the strike on Midway by a day because Nagumo’s force had left Japan a day late.

The strike on the base was entrusted to the 2nd Carrier Striking Force of Rear Admiral Kakuji Kakuta. He had two carriers: the light pre-war Ryūjō and Jun’yō, converted from a passenger liner, which had entered service only on 3 May 1942. They were screened by the heavy cruisers Takao and Maya and three destroyers. Compared with Chūichi Nagumo’s four carriers it was a modest force, but in the far north it had no opponent at sea.

The Americans in Alaska

The Americans knew the enemy’s general intentions. In May the cryptanalysts at Pearl Harbor had read enough Japanese traffic for Admiral Chester Nimitz to know of the planned attack on the Aleutians, its approximate timing and the participation of two carriers. He had no intention, however, of sending any of his three carriers north; all of them were waiting for the Japanese off Midway. To Alaska he sent Rear Admiral Robert Theobald’s Task Force 8: five cruisers, more than a dozen destroyers and submarines, together with naval aviation with Catalina flying boats and the Army Air Forces’ Eleventh Air Force.

Theobald did not fully trust the intelligence findings. He believed that the Japanese might attack Dutch Harbor only as a diversion and deliver the real blow further east, against Kodiak or mainland Alaska. He therefore concentrated his cruisers in the waters south of Kodiak, several hundred miles from Dutch Harbor, and put to sea himself in the cruiser Nashville, which kept radio silence. During both raids his ships had no contact with the enemy, and the lack of communication with their commander hampered the direction of the scattered air forces. Many historians later judged these decisions critically.

The base itself was better prepared than the Japanese believed. Dutch Harbor was defended by the anti-aircraft guns of the 206th Coast Artillery Regiment of the Arkansas National Guard, stationed on the island since the autumn of 1941, and by the garrison of Fort Mears. Above all, Japanese intelligence did not know that in March 1942 an airfield had been built in secret on the neighbouring island of Umnak, disguised as a fish cannery, from which P-40 fighters operated. A second airfield had been built at Cold Bay on the Alaska Peninsula. The Japanese believed that the nearest American airfield was on Kodiak.

On the afternoon of 2 June a Catalina flying boat sighted the Japanese force several hundred miles south-west of Dutch Harbor. Soon afterwards fog rolled in and contact was lost. The garrison was put on alert, but received no specific warning of the attack itself.

The first raid: 3 June

Kakuta launched his aircraft about 180 nautical miles from the target, in darkness and bad weather. According to American tallies, the first wave consisted of 12 Zero fighters, 10 level bombers and 12 dive-bombers. The group from Jun’yō got lost in the fog and turned back; only a dozen or so aircraft, mainly from Ryūjō, reached Dutch Harbor. Bombs fell on fuel tanks, the radio station and barracks. The heaviest casualties were caused by a hit on two huts at Fort Mears, where 25 infantrymen and engineers were killed. The gunners from Arkansas, without waiting for orders, ran to their guns and opened fire; accounts recall that men were even firing rifles. Surprised by the fire, the Japanese dropped their bombs in haste and flew off.

Japanese reconnaissance floatplanes from Takao and Maya, searching for ships in the area, ran into American fighters. This was how the Japanese first discovered that American land-based aircraft were operating in the area. During the night of 3–4 June the gunners moved some of the guns from the hills into the town of Unalaska and the harbour, partly to mislead the enemy and partly for fear of a landing.

The second raid: 4 June

On 4 June Kakuta closed in to less than 100 miles from the island. In the morning the weather frustrated another attempt, but in the afternoon a second wave, larger and better organised, reached the base: some nine fighters, eleven dive-bombers and six level bombers. This time fuel tanks went up in flames, and a wing of the hospital, a hangar and an anti-aircraft gun position were destroyed. The airmen, believing they were attacking a large warship, badly damaged the old ship Northwestern, which had been beached and was serving as a hotel for construction workers; the hull was saved, and its power plant later supplied the base with steam and electricity.

On the way back some of the Japanese aircraft gathered over the western end of Unalaska, near Umnak, and there ran into a patrol of P-40s from the hidden airfield. In a brief fight the Americans lost two P-40s and the Japanese, according to American figures, three aircraft. Anti-aircraft fire also hit a Zero from Ryūjō flown by a nineteen-year-old petty officer, Tadayoshi Koga. According to the American author Jim Rearden, it was probably Koga’s section that shot down an American Catalina during this raid and strafed its crew in the water; none of the seven airmen survived. With a severed oil line, Koga flew to Akutan island, designated for emergency landings, where a Japanese submarine was waiting. The grassy meadow turned out to be a bog: the aircraft landed with its wheels down, dug in and flipped over onto its back. The pilot was killed, probably by a broken neck, while the machine survived almost intact. Koga’s comrades had orders to destroy damaged Zeros on enemy territory, but, not knowing whether their comrade was alive, they flew off without firing a shot.

American aircraft, meanwhile, were trying to find and sink the Japanese carriers. Catalina flying boats repeatedly sighted Kakuta’s force, and B-26 and B-17 bombers from Umnak and Cold Bay attacked it with bombs and torpedoes. No attack scored a hit, and time and again the fog allowed the Japanese to disappear.

The balance

According to American tallies, 43 Americans were killed in the two raids, the vast majority of them servicemen, and about 50 were wounded. According to figures cited in the literature, the Eleventh Air Force lost four B-17s, two B-26s and two P-40s in those days, counting accidents and aircraft lost in bad weather, and the navy six Catalinas. The Japanese lost no ships, and their aircraft losses, variously reported, amounted to at least several machines. The damage at Dutch Harbor was serious, but the base was not put out of action.

At Midway, meanwhile, the decisive battle was beginning. On 4 June, a few hours before the second raid on Dutch Harbor, American dive-bombers set three of Nagumo’s carriers on fire, and a fourth in the afternoon. Yamamoto tried to retrieve the situation: he summoned Kakuta south to reinforce what remained of his forces in the central Pacific, and briefly suspended the Aleutian operation. The attack on Adak was abandoned. The occupation of Kiska and Attu was nevertheless carried out in the end, though without the support that had been counted on. Kakuta’s carriers never reached Midway and had no influence on the outcome of the battle, and two ships that might have reinforced Nagumo spent the decisive days in the north.

The Akutan Zero

The most lasting consequence of the raids proved to be the wreck of Koga’s aircraft. It lay in the bog, invisible from the sea and from the usual flight paths, for more than a month. On 10 July it was spotted by the crew of a Catalina that had lost its way on patrol. Over the following days teams from Dutch Harbor buried the pilot, extracted the machine from the mud and shipped it via Seattle to the naval air station at North Island near San Diego. After repairs the aircraft took to the air on 20 September 1942, in American markings, and went through a series of test flights, including mock combats with American fighters.

It was the first practically undamaged Zero the Americans had captured in the war. The tests confirmed its manoeuvrability and range but also revealed its weaknesses: no armour and no self-sealing tanks, ailerons that stiffened at high speed, and a carburettor that cut the engine under negative g. American pilots were given specific advice on how to escape a Zero by diving and turning sharply. The Japanese naval aviator and historian Masatake Okumiya later wrote that the loss of this aircraft was no less serious for Japan than the defeat at Midway. Many historians, among them John Lundstrom, consider this an exaggeration: the Grumman F6F Hellcat fighter had been designed before the wreck was found, and American airmen had already worked out effective tactics against the Zero. The prize from Akutan nevertheless remains one of the most valuable trophies of technical intelligence in the Pacific War.

Place in the war

The attack on Dutch Harbor opened the Aleutian campaign, the only land campaign of the war fought on United States territory in North America. On 6 and 7 June the Japanese landed unopposed on Kiska and Attu. The Americans feared that this was the prelude to an attack on mainland Alaska or even on the West Coast; more than 2,000 soldiers were flown to Nome in military and requisitioned civilian aircraft, and in June and July several hundred Aleuts were removed from the threatened islands to makeshift camps in south-eastern Alaska, where dozens of them died.

Militarily, the Aleutians remained a secondary theatre, where the weather – fog, gales and cold – killed more often than the enemy. The Americans built more and more airfields ever closer to the Japanese-held islands; in May 1943, after heavy fighting, they retook Attu, and in August they landed on Kiska, which the Japanese garrison had already secretly evacuated. Dutch Harbor itself remained the main base of this front until the end of the war.

In the wider picture, Operation AL was part of a plan that failed. Kakuta’s two carriers and their supporting ships contributed nothing to the battle on which the fate of the Japanese fleet depended, and the captured islands – remote, fog-bound and difficult to supply – tied down Japanese forces for a year without any real benefit. What survived longest from the raids on Dutch Harbor was the wreck of a single fighter, from which the Americans read the secrets of what was then the enemy’s most dangerous aircraft.