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— CH. 1 · INTRODUCTION —

Operation Ke

~11 min read · Ch. 1 of 7
7 sections
  • Operation Ke was the largely successful withdrawal of Japanese forces from Guadalcanal, concluding a six-month struggle that had defined the Pacific War's first year. Between the 14th of January and the 7th of February 1943, Imperial Japanese Army and Navy forces pulled off something the Allies never saw coming: they turned a defeat into a disciplined escape.

    By the time the operation began, the Japanese had delivered nearly 36,000 troops to Guadalcanal since the campaign started. Only about 11,000 remained alive on the island. The rest had been killed in battle, or killed more slowly by starvation and disease. Three multiple attempts to retake Henderson Field had all failed. The navy was bleeding destroyers trying to keep the survivors fed.

    So the question facing Japan's high command in late 1942 was not whether to keep fighting for Guadalcanal, but how to save the men still alive there without the Allies realizing what was happening. Admiral Isoroku Yamamoto and General Hitoshi Imamura were among the commanders charged with answering that question. What they devised was a plan so convincingly disguised that, when the last destroyer left Guadalcanal in the early hours of the 8th of February, American forces still believed they had been watching a reinforcement operation.

  • Takushiro Hattori and Masanobu Tsuji, both of whom had recently visited Guadalcanal, told their colleagues in Tokyo that any further attempt to retake the island was a lost cause. Their reports landed in November 1942 and set off a quiet internal debate that the top brass had not yet authorized publicly.

    Ryuzo Sejima, another staff officer, reported that the attrition of Japanese Army troop strength on Guadalcanal was so unexpectedly severe that future operations would be untenable. By early December, IJA forces were losing about 50 men each day to malnutrition, disease, and Allied attacks. The few supply runs that got through were not enough.

    On the 11th of December, two officers, IJN Commander Yuji Yamamoto and IJA Major Takahiko Hayashi, returned to Tokyo from Rabaul and confirmed what the earlier reports had said. They added that most IJN and IJA officers at Rabaul appeared to support abandoning Guadalcanal entirely. Around the same time, Japan's War Ministry told the high command there was insufficient shipping to sustain both the Guadalcanal effort and the transport of resources needed to keep Japan's economy and military running.

    Japan's navy had already been quietly planning for withdrawal, without telling the army. Combined Fleet leaders at Truk, under Yamamoto's overall command, had concluded that Allied advances in New Guinea posed a greater threat to the empire than losing the southern Solomons. IJN staff officers had begun drafting plans to abandon Guadalcanal and shift resources to New Guinea even before the army knew the conversation was happening.

    On the 19th of December, IGH Colonel Joichiro Sanada led a delegation to Rabaul. Hitoshi Imamura, commanding the 8th Area Army, did not formally recommend withdrawal but described the situation plainly enough. He said any decision to pull out should include a plan to evacuate as many soldiers as possible. Sanada returned to Tokyo on the 25th of December and recommended immediate abandonment. The IGH's top leaders agreed the next day and ordered their staffs to begin drafting plans. On the 28th of December, General Hajime Sugiyama and Admiral Osami Nagano personally informed Emperor Hirohito of the decision. The Emperor formally endorsed it on the 31st of December 1942.

  • By the 9th of January 1943, the Combined Fleet and 8th Area Army staffs had together completed the evacuation plan. It was named Operation Ke after a mora in Japanese Kana vocabulary.

    The plan had four moving parts. A battalion of infantry would land by destroyer around the 14th of January to act as a rear guard. The 17th Army would withdraw to the western end of the island around the 25th or the 26th of January. An air superiority campaign around the southern Solomons would begin on the 28th of January. Then, in the first week of February, destroyers would lift the surviving troops in three separate runs, with a target completion date of the 10th of February.

    To cover what was actually happening, Japanese air and naval forces would conduct visible maneuvers near New Guinea and the Marshall Islands. Deceptive radio traffic was also designed to suggest an impending offensive rather than a retreat. On the 1st of January, the Japanese military changed their radio communication codes, making it harder for Allied intelligence, which had previously partially broken Japanese ciphers, to read what was being planned.

    Yamamoto assigned aircraft carriers, battleships, and heavy cruisers under Nobutake Kondo to provide distant cover from the area around Ontong Java in the northern Solomons. The actual evacuation runs would be executed by destroyers gathered at the Shortland Islands, 21 in total. The air superiority portion of the operation drew support from the IJN's 11th Air Fleet with 212 aircraft and the IJA's 6th Air Division with 100 aircraft, both based at Rabaul, along with 64 aircraft temporarily transferred from carrier air groups and 60 floatplanes from the R Area Air Force. The combined Japanese air total came to 436 aircraft. The Allies could field around 539 aircraft to oppose the operation, though they would be spending much of that strength preparing for a Japanese offensive that was not coming.

    Yamamoto was clear-eyed about the cost. He expected that at least half of his destroyers would be sunk during the operation.

  • On the 14th of January, nine destroyers delivered the Yano Battalion to Guadalcanal. The battalion, commanded by Major Keiji Yano, consisted of 750 infantry and a battery of mountain guns crewed by another 100 men. Traveling with them was Lieutenant Colonel Kumao Imoto, representing the 8th Area Army. His task was to carry the evacuation order to 17th Army commander Lieutenant General Harukichi Hyakutake. Hyakutake and his staff did not yet know they were leaving.

    Late on the 15th of January, Imoto reached 17th Army headquarters at Kokumbona and delivered the news. Hyakutake accepted the order on the 16th of January, though his recorded words were far from enthusiastic. "It is a very difficult task for the army to withdraw under existing circumstances," he said. "However, the orders of the Area Army, based upon orders of the Emperor, must be carried out at any cost. I cannot guarantee it can be completely carried out."

    The 17th Army communicated the plan to its forces on the 18th of January. The orders directed the 38th Division to disengage from the inland ridges and hills it was defending against an American offensive and withdraw toward Cape Esperance on the western end of Guadalcanal, beginning on the 20th of January. The 2nd Infantry Division, which had been on Guadalcanal since October 1942, and the Yano Battalion would cover the 38th's retreat, then follow westward. Any troops too sick or injured to move were encouraged to kill themselves to uphold the honor of the Imperial Army.

    By the first week of January, disease, starvation, and battle had cut Hyakutake's command to about 14,000 men, many of them too sick and malnourished to fight. His army possessed three operable field cannon with very little ammunition. Against them, the Allied commander on the island, US Army Major General Alexander Patch, fielded a combined force of US Army and Marines numbering 50,666 men and 167 artillery weapons, including 75 mm, 105 mm, and 155 mm howitzers.

  • Allied analysts watching the buildup of ships and aircraft at Truk, Rabaul, and the Shortland Islands concluded something was coming. On the 26th of January, the Allied Pacific Command's intelligence section formally warned Allied forces in the Pacific that the Japanese were preparing for a new offensive called Ke in either the Solomons or New Guinea. The warning had the right name and the wrong meaning.

    Admiral William Halsey Jr., commanding Allied naval forces in the South Pacific, responded by sending a resupply convoy to Guadalcanal on the 29th of January, supported by a large warship force split across five task forces. These included two fleet carriers, two escort carriers, three battleships, 12 cruisers, and 25 destroyers. Halsey was positioning his fleet to meet a Japanese attack that was not going to come.

    The Japanese air campaign meanwhile achieved something tangible. On the 29th of January, 16 G4M torpedo bombers from the 705 Air Group and 16 Mitsubishi G3M Nell bombers from the 701 Air Group took off from Rabaul and attacked Task Force 18 under Rear Admiral Robert C. Giffen. Two torpedoes struck the heavy cruiser Chicago, bringing her to a dead stop. The following day, a flight of 11 Mitsubishi torpedo bombers from the 751 Air Group attacked the force towing Chicago. Fighter aircraft from the carrier Enterprise shot down eight of the attackers, but four more torpedoes hit Chicago and sank her. A US destroyer was also hit and heavily damaged in the fighting.

    On the 29th of January, two Royal New Zealand Navy corvettes intercepted the Japanese submarine I-1 off Kamimbo on Guadalcanal. The corvettes rammed and sank I-1 after a 90-minute battle, a small footnote in a week dominated by larger actions. The departure of Giffen's task force from the Guadalcanal area after the Chicago incident, which Halsey ordered for the following day, removed one of the more significant potential threats to the evacuation runs still to come.

  • Rear Admiral Shintaro Hashimoto departed the Shortland Islands at 11:30 on the 1st of February with 20 destroyers for the first evacuation run. Eleven were designated transports; nine were screening ships. CAF aircraft attacked in two waves in the late afternoon near Vangunu, with 92 aircraft in total. Hashimoto's flagship was heavily damaged by a near miss. He transferred his flag and detached another destroyer to tow the crippled ship back to base.

    Eleven US PT boats awaited Hashimoto between Guadalcanal and Savo Island. Beginning at 22:45, the two forces engaged in running battles over three hours. Hashimoto's destroyers, with help from R Area floatplanes, sank three of the PT boats.

    At the pick-up points off Cape Esperance and Kamimbo, Japanese naval personnel ferried the waiting troops out to the destroyers in barges and landing craft. Rear Admiral Tomiji Koyanagi, second-in-command of the Reinforcement Unit, described what he saw: "They wore only the remains of clothes that were so soiled their physical deterioration was extreme. Probably they were happy but they showed no expression. Their digestive organs were so completely destroyed, we couldn't give them good food, only porridge." Another officer added that the men's bodies had deteriorated so severely they suffered from constant and uncontrolled diarrhea aboard the destroyers.

    After embarking 4,935 soldiers, mainly from the 38th Division, loading ceased at 01:58. Then one of the screening destroyers, Makigumo, was suddenly wracked by a large explosion, caused by either a PT boat torpedo or a naval mine. Hashimoto ordered her abandoned and scuttled. The Reinforcement Unit returned to the Shortlands by 12:00 on the 2nd of February, with one destroyer lost and Hashimoto's original flagship also out of action.

    The second run on the 4th of February lifted 3,921 men, mainly from the 2nd Division, including Hyakutake and his staff. The US PT boats did not sortie that night and the loading went without incident. Hashimoto's force reached Bougainville by 12:50 on the 5th of February. American commanders on Guadalcanal, Patch included, interpreted both the first and second runs as reinforcement missions. They continued their advance at a cautious pace of about 900 yards per day.

    The third run on the 7th of February carried 1,972 more soldiers. For an additional 90 minutes after the last man was loaded, destroyer crewmen rowed along the shore calling out to make sure no one was left behind. At 01:32 on the 8th of February, the Reinforcement Group left Guadalcanal and reached Bougainville at 10:00.

  • At dawn on the 8th of February, US Army forces advancing on both the north and south coasts of Guadalcanal found almost nothing. Only a few sick and dying Japanese soldiers remained. Patch now understood what the Tokyo Express runs had actually been.

    At 16:50 on the 9th of February, the two American forces met at the village of Tenaro on the west coast. Patch sent Halsey a message: "Total and complete defeat of Japanese forces on Guadalcanal effected 16:25 today... the Tokyo Express no longer has a terminus on Guadalcanal."

    The Japanese had evacuated 10,652 men, roughly all that remained of the 36,000 troops sent to the island during the campaign. Six hundred of the evacuees died from their injuries or illnesses before receiving adequate medical care. Three thousand more required lengthy hospitalization. The operation cost the Japanese one destroyer sunk and three damaged.

    Admiral Chester Nimitz, commander of Allied forces in the Pacific, later assessed the operation plainly. "Until the last moment it appeared that the Japanese were attempting a major reinforcement effort," he wrote. "Only the skill in keeping their plans disguised and bold celerity in carrying them out enabled the Japanese to withdraw the remnants of the Guadalcanal garrison. Not until all organized forces had been evacuated on the 8th of February did we realize the purpose of their air and naval dispositions."

    Historians later faulted Patch and Halsey for failing to exploit their ground, air, and naval superiority to prevent the evacuation. The 2nd Division was reconstituted and relocated to the Philippines in March 1943. The 38th Division was assigned to defend Rabaul and New Ireland. The 17th Army was rebuilt around the 6th Infantry Division and repositioned on Bougainville. The last known Japanese holdout on Guadalcanal surrendered in October 1947, more than four years after the last destroyer had sailed away.

Common questions

What was Operation Ke in World War II?

Operation Ke was the Japanese withdrawal from Guadalcanal, carried out between the 14th of January and the 7th of February 1943. It successfully evacuated 10,652 surviving Japanese troops from the island, concluding the six-month Guadalcanal Campaign. The operation was disguised as a reinforcement effort and was not recognized as an evacuation by Allied forces until it was already complete.

Who commanded Operation Ke?

Operation Ke was directed by the Japanese Imperial General Headquarters, with Admiral Isoroku Yamamoto and General Hitoshi Imamura among the key commanders. The destroyer evacuation runs were led by Rear Admiral Shintaro Hashimoto, who commanded the Reinforcement Unit at the Shortland Islands.

How many Japanese troops were evacuated from Guadalcanal during Operation Ke?

A total of 10,652 Japanese troops were evacuated from Guadalcanal across three destroyer runs on the nights of the 1st, 4th, and the 7th of February 1943. Six hundred of those evacuated died from injuries or illness before receiving adequate medical care, and 3,000 more required lengthy hospitalization.

Why did Japan decide to withdraw from Guadalcanal?

Japan withdrew because repeated attempts to recapture Henderson Field had all failed with heavy losses, and Japanese ground forces on the island had been reduced from 36,000 to roughly 11,000 through starvation, disease, and combat. The Imperial Japanese Navy was also suffering unsustainable losses trying to resupply and reinforce the garrison. Emperor Hirohito formally endorsed the decision to withdraw on the 31st of December 1942.

How did Japan keep Operation Ke secret from the Allies?

Japan used deceptive radio traffic around New Guinea and the Marshall Islands to suggest an impending offensive rather than a retreat. Japanese forces also changed their radio communication codes on the 1st of January 1943, making Allied interception harder. Allied intelligence correctly identified the operation by its code name Ke but misidentified it as a new offensive, not a withdrawal.

What happened to Japanese soldiers who could not be evacuated from Guadalcanal?

Japanese soldiers too sick or injured to move were ordered to kill themselves to uphold the honor of the Imperial Army. A small number of stragglers remained on the island after the evacuation; many were killed or captured by Allied patrols in the years that followed. The last known Japanese holdout on Guadalcanal surrendered in October 1947.