World War II Pacific Island Territories: The Marshall Islands

Figure 1.--Many youths were involved in the fighting on both sides. Tenagers as young as 17 years of age could volunteer for American military service with their parents approval. Here Marines on Eniwetok sshow tghe strains of combat (February 17, 1944). Many lessons learned on Tarawa at great cost were used in the Marshalls to limit losses.

Japan seized the Marshall Islands during World War I (1914). The League of Nations awarded a mandate to the Japanese after the War. The Japanese set up their administration Jaluit which had been the German administrative center. The penetration of the outer shell of Japanese islands in the south was followed by assauilts on the outer shell of Japanese islasnd defenses in the Central Pacific. The Japanese heavily fortified their island bastionss in preparation. New carriers and planes were beginning to reach the U.S. Pacific fleet. The American plan to defeat Japan was centered on a drive across the Central Pacific. Here the outer perimeter of the Japanese defenses were the Gilbert and Marshall Islands. The Japanese when they launched the war sought to destroy the U.S. Pacific fleet. The Imperial Fleet would then protect the expanded Empire. The elite corps of Japanese carrier pilots were lost during a series of naval engagements (Coral Sea, Midway and the Solomons campaign) during 1942. As a result, the Imperial Navy did not oppose the American invasion of the Marshalls, hopeing that well entrrenched and equipped garisons could fend off amphibious invasions. The U.S. Marines and Army forces proved they could not. The Marines and Army supported by the U.S. Navy took both Kwajalein and Eniwetok Atolls in bloody invasions. Lessons learned at Tarawa were implemented to limit losses. The Marines landed on Kwajalein atoll (January 31, 1944). The United States quickly took control of the islands. They were then turned into gforward bases to target the Carolines and ultimarely the Marianas. The logistics of amfibious operations were greatly aided by nearby land bases for support.

The Islands

The Marshalls Islands are two basically parallel north/south orientefd chains situated about 100 miles apart. The eastern islands were rferred to as the sunrise chain and are made up of Mille, Maloelap, and Wotje atols. The western or sunset chain includes Bikini, Eniwetok, Jaluit, Kwajalein, and Rongelap atols. These were just the major atols, there were many smaller atols. Kwajaleinis the world's largest coral atoll with over 90 small islands. It is located in the geographic center of the Marshalls and is about 2,100 nautical miles southwest of Pearl Harbor. Much closer were the Gilberts to the southeast.

Background History

The Europeans to vist the Marshalls were Spanish explorers (early 16th century). The Islands are name after a British captain who visited them (1788). Considerable mapping was done on Russian expeditions under Adam Johann von Krusenstern (1803) and Otto von Kotzebue (1815 and 1823). The Marshall Islands were not claimed by a European power until Spain claimed them (1874). The Germans at the time were actively building an Empire, but most of Africa and Asia was already claimed by other European powers. Germany also claimed the islands. The Pope helped mediate the dispute between Spain and Germany. The Germans paid the Spanish $4.5 million and Spain in return recognized Germany's claim (1885). The Germans established a protectorate over the islands and opened trading stations on Jaluit and Ebon to develop the copra (dried coconut meat) trade. This continues to be a key part of the Island's econonmy. Marshallese Iroij (high chiefs) continued internal rule supervised by the German colonial administration. The Germans were not very successful. Administrative affairs were managed by private German and Australian commercial interests.


The population of the Marshall Islands are of Micronesian origin. This means people who began a series of migrations from Southeast Asia. The population has a matrilineal culture organized on a complex system of clans and lineages based on land ownership. Most of the population is Christian, primarily Protestant. Only 4 islands and 19 atolls are actually inhabited. The terrains is primarly coral, limestone, and sand. This limits the population that can be supported. The total area of the islands is 181 square kilometers, about 60 percent of which is farmed. About half the population is located on Majuro Atol. We are not sure about the civilian population of the Marshalls was at the time of the War, but it seems less than 10,000 people.

Japanese Colonial Administration

Japan seized the islands from the Germans during World War I (1914). The League of Nations awarded a mandate to the Japanese after the War under the authority of Article 22 of the League of Nations Charter. The Japanese set up their administration at Jaluit which had been the German administrative center. The Marshalls were referred to as the Eastern Mandates. The Japanese after World War I settled about 1,000 Japanese civilians on the Marshalls in addition to military personnel. The Japanese set out to reshape the local culture in the Japanese image. The Japanese seized coastal land, the best agricultural land, and attempted to reshape the social struicture from the indegenous Matrilineality to the Japanese Patriarchal system. Instruction in the schools was in Japanese. At the time of World War II, the road network was still minimal. As Japan began to move toward war (late-1930s), they began to militarize the islands with the idea of expansionism south and toward othervislands in Oceania. This was a violation of the League of Nations Mandate under which the islands had been administered, but Japan had withdrawn from the League (1934). The Japanese had, however, on at least one of the islands in the major atol group built airstrips. They also constructed barracks, airfields, piers, and other basic military installations throughout the islands. To build military instlations, the Japanese dispatched Korean forced laborers (early-1940s). These men were conscripted. Over 10,000 Koreans were were sent to Micronesia (Nanyo Gunto). Most came from southern Korea and many were sent to the Marshall Islands. In some atolls, such as Wotje, the Koreans were joined by Japanese prisoners from Hokkaido -- largely political prisoners who had criticized the Japanese government. On Kwajalein, Koreans were organized in battalions and other specialized groups, sometimes with Marshallese conscripted locallu. They built fortifications throughout the atoll. When the American air raids began, the construction teams had to labor night and day to repair the damge, especially any craters in the air strip runway. The construction projects were still underway when the Americans invaded.

Pearl Harbor (December 1941)

Japan launched the Pacific War with a devestaing carrier strike on the American naval base at Pearl Harbor (December 1941). The primary goal of the attack was to destroy the American carriers at Pearl. Adminral Yamamoto understood better than many of his colleagues the importance of carriers in modern naval war. The Pearl Harbor attack crippled the American Pacific Fleet, destroying or sinking the eight battleships of the Fleet. Most naval experts at the time considered battleships to be the backbone of the fleet. his is why the battleships had been moved forward from San Diego to Pearl Harbor. The Army Air Corps air contingent was also largely destroyed. By a fortunate stroke of luck, the carriers were not at Pearl. Thus the U.S. Pacific Fleet was crippeled, but not destroyed. And because Admiral Nagumo did not order a third strike on the dry docks, fuel tanks, and warehouses, the First Air Fllet departedPear leaving it a battered, but stil; functioning and potent naval base.

American Carrier Strikes (January 1942)

While the three American carriers survived Pearl Harbor, they were outnumbered by the six Japanese mainline fleet carriers and did not have adequatte support vessels to risk a fleet engagement. Thus the carriers had to be used to buy time. Even more important, the American carriers were not yet ready to engage the Japanese. They were not as well trained as the Japanese and had no experience in coordinated fleet operations. And there were a range of other problems which only surfaced after the War began. American torpedoes had serious problems. Some of the Japanese planes, especially the Zero, outclassed American planes. Less fully understood at the onset was how well trained the Japanese pilots were and they also had real battle experience. Tactics were not yet available to deal with the Zero. Admiral Ninmitz was not fully aware of these problems immediately after Pearl, but he was aware that the Japanese carriers outnumbered his carriers two to one. So Nimitz decided to use the carriers in hit and run attacks on the Japanese island bases to help the carriers prepare for the inevitable show-down withbthe Japanese carriers. The Pacific was a big place. Thus these attacks would be hard for the Japanese to stop. And they had the vantage of allowing the American carrier crews and air crew to gain needed experience. The Marshalls were the first to be attacked (January 1942).

Crucial Japanese Error

Given the indudtrial mismatch, it was inevitable that America would win any protracted War. Thus the sooner the Japanese engaged and destroyed the American carriers, the better. Never again would the available forces be stacked in Japan's favor. Any delay would only allow the Americans to strenthen their fleet and rebuild Pearl's defenses as well as the American carriers and air groups to improve their battle readybness. Nimitz did not seek a fleet ction, but the Japanese could have. An attack on an important asset such as Pearl or Australia would have forced Ninmitz to commit his carriers. Yamamoto instead dithered. To some cextent this was a part of the Japanese offensive into the South Pacific, but there was clearly a lack of urgency. Inexplicably a carrier group was sent into the Indian Ocean (April 1942). Only the American Dolittle Raid on Tokyo re-focused Yamamoto's focus on the American carriers. But by this time the Pavific Fleet had been reeforced somewhat and the American carriers were much more prepared for battle. The result was the first carrier battles of rge War: the Coral Sea (May 1942) at Midway June 1942). The destruction of four fleet carriers at Midway even the ballance of forces and bought the Pacific Fleet the time it need for American shipyards to build a huge number of modern new vessels.

Japanese Strategy: The Outer Perimiter

The Gilbert and Marshall Islands were the outer perimeter of the Japanese Empire in the Central Pacific. The Japanese when they launched the war sought to destroy the U.S. Pacific fleet. The Imperial Fleet would then protect the expanded Empire. After the start of the War, the Japanese began to further fortify the islands, especially in 1943 when it became obvious that the U.S. Navy was preparing anphibious invasions. The Japanese Imperial General Staff adopted a new strategy (September 1943). The lossdes at Midway had been followed by further huge naval and air losses in the South Pacific, both in the Solomons and New Guinea. The elite corps of Japanese carrier pilots were lost during a series of naval engagements (Coral Sea, Midway and the Solomons campaign) during 1942. The Japanse decided to husband their dwindling resources for the defense of the Western Pacific. The Marshalls were an easterly Japanese Pacific possession and thus a likely target of the rapidly expanding Pacific fleet. As a result the Imperial Navy did not oppose the American invasion of the Marshalls, hopeing that well entrrenched and equipped garisons could fend off amphibious invasions. The Japanese throughout 1943 were reinforcing their island bastions and strenghtening their defenses, although expanding American navalm power was making it difficult to supply these bastions, let along reinforce them. .

Preparing for Invasion

After Midway (June 1942) and Guadalcanal (August-December 1942), it was obvious that the Americans would begin trgeting the Central Oacific. The Japanese begn strenghening its Central Pacific island defenses. A Japanese naval, air, and ground forces was dispatched to Kwajalein (early-1943). They were units tght had been stantioned in Mnchukuo. Most were young and inexperienced (18 and 21) and were unprepared for tropical conditions. Many of the supply ships that were meant to support and feed them were sunk by American submarines. As a result they had a very difficult existence on Kwajalein where food was already in short supply. Many contracted illness like dengue fever and dysentery. The Korean laborers were in the same situation.

American Strategy (May 1943)

The United States Joint Chiefs of Staff (JCS) presented their "Strategic Plan for the Defeat of Japan" during the Anglo-American Washington Conference (May 1943). American industry was finally delivering the war material providing the American military the capability of intensifying operations in the Pacific theater. Up until this point in the War, the fighting had been primarily conducted by the British on the Indian border with Burma and by the Army in the Solomons and New Guinea, although this was only made possible by costly Naval battles. Adminral King wanted this changed. And he pursued his vision of the War at Allied naval conferences (Trident and Quadrant). He wanted a focus on interdicting Japan's Western Pacific sea lanes, cutting Japan off from the resources it had won in its Southern Resource Zone. At this stagec of the War, President Roosevelt was losing confidence in Chiang Kai-shek and the willingness of the British to coimmit needed forces to Southeast Asia. Admiral King pressed foe approval of a new Navy plab--'Agreed essentials in the conduct iof tge War' (CCS 242/6). The President and Prime-Mimister Churchill approved (May 25, 1943). This essentially made the war with Japan an American responsibility. Admiral Nimitz and the Navy was directed to conduct the primary campaign in large measure because the Central Pacific provided the the shorter, more direct approach to Japan. General MacArthur much to his displeasure was directed to conduct a secondary campaign that would support Nimitz's effort. The two campaigns would complement each other as the Japanese would be engaged over a wide expanse of territory and would be kept guessing where the next blow would fall. The basic JCS plan would prove to be the blueprint for not only demolishing the Japanese Pacific Empire, but to the eventual surrebder of the Home Islands. Admiral Nimitz was confronted with the largest battlefield ever assigned to a military commander--the vast straches of the Pacifuc Ocean. The strategy he develooed was to seizing one island chain which was then used to support operations on the next chain. The logistics of amfibious operations were greatly aided by nearby land bases for support.

The Gilberts (November 1943)

Once Admiral King had made the Central Pacific the Navy's principal Pacific priority, planning the details became Admiral Nimitz's resonsibility. Nimitz's first target was the Gilbert Islands. There was some debate about this. Some of his staff wanted to bypass the Gilberts and hit the Marshalls. They finally decided to hit what they thought would be a realtively soft target--Tarawa Atoll. In retrospect this proved to be a serious miscalculation and underestimation of the Japanese. The Gilberts were 565 nautical miles southeast of the Marshalls. The Japanese could not fortify and garrison every island in the Pacific. The U.S. Army's 27th Infantry Division seized Makin Island with only limited Japanese resistance. Tarawa proved a very different matter. The U.S. 2d Marine Division was shattered by heavily entrnched Japanese defenders who fought to the death. The Marines finally took Tarawa but only after suffering appalling losses. To the surproise of American planners, the Imperial Fleet did not oppose the American invasions. Tarawa was very different tham the island invasions in the Sollomons. It was the first American amfibious invasion of a heavily fortified Japanese island. Not surprisingly many problems were found in the operation. Naval preinvasion bombardments proved ineffective against Japanese fortifications. Air support proved inadequate to support the marines. Communications was the principal problem. The Marines were inadequately equipped. In particular there was a shortahe of tracked landing craft. Despite these problems, the Marines proved that the U.S. Navy amphibious forces were capable of taking heavily fortified Japanese bases. The Navy carefully studdied the Tarawa landings and the lessons leaned there would be used to better plan subsequent operations. The United States immediately began establishing Tarawa and Mankin as forward bases for the next target--the Gilberts. Air bases there brought the Marshalls within range of land-based air attacks. American aircraft could now conduct combat and photographic reconoisance missions throughout the Central Pacific. The immediate target was the Marshalls.

Operation Flintlock--American Invasions (January-February 1944)

The U.S. Marines proved in the Gilberts that cut off island garrisons could not hold. The Marines and Army supported by the U.S. Navy next assaulted the Marshall Islands. They were further west and closer to the Marianas, but still the Imperial fleet was not expected to intervene even though it would put Truk in jepordy. Both the Navy and Marines learned from their bloody exoeriences in the Gilberts. Naval gunners and airmen practiced in Hawaii. Better landing craft were available. Nimitz decided to focus the attack on Kwajalein and simoly bypass most of the other islands. Efforts were also made to improve radio commuications between the Marines and the fleet with air and naval spotters going ashore with the Marines. The Marines this time had greater fire support as well as heavily asrmed amstracks. Naval gunfire and air assaults raked Kwajalein for 3 days with far greater accuracy than in the Gilberts. Frogmen blew holes in the reef at key locations. The Marines landed (January 31). Kwajalein was taken in 4 days with less than 2,000 casualties. This success and the lack of any indication that the Imperial Fleet would intervene caused Nimitz to move up the assault on Eniwetok from May 1 to February 17. Forces were available because Kwajalein proved less costly than abticipated and the other islands had been bipassed. Eniwetok was 1,000 miles further west, but as dexpected the Imperial Fleet did not intervene. The Americans landed 8,000 men, two reinforced regiments (February 17). They were opposed by 2,000 Japanrse. Mistakes were made, especially with the naval gunfire. The Japoanese resisted tenaciously, almost to a man. But the island was in American hands (February 22). The cost was less than expected--about 1,000 casualties including 300 killed.

Remaining Islands

The United States did not invade all of the Marshall Islands. In just one month, the Americans captured Kwajalein Atoll, Majuro, and Enewetak. Amd during the next 2wo months, the rest of the Marshall Islands, except for Wotje, Mili, Maloelap and Jaluit. American inteligence discovered that the Japanese had heavily fortified the outer islands and this wen right for Kwajalein and Enewetak. This broke Japanese power in the islands. Without planes and ships, the japanese garisons on the bu-passed ialands were of no military importance. and could ot resist the American push west toward the all-important Marianas. The American bombed the remaining islands. That was, however, not the greatest threat. The Japanese soldiers and population were left with ;ittle or no food. The Japanese had cramed the smll atols with so many men that they could not possibly grow enough food to feed themselves. Reams have been written about Japanee atrocities duting the War. Often ignored are the atrocities that the Japanese miltarists commitd aginst their own people and solduers. The Japanee soldiers on the rmiing islnds were ot permutted to surender. Rther thy were cinmbed y=to die a long painful death from starvation. Half the Japanese garrison of 5,100 people on the Mili atol died from starvation by the time the Japanese Government surrendered (August 1945). [Spennemann]


American possession of the Marshlls substntilly changed the strategic balance in the Centrl Pacific. The victory gave the U.S. Pacific fleet needed bases to support the the critical Marianas campaign. It also rendered the Japanese position on Truk in the Carolines untenable. The Japabese once called Truk the Gibraltar of the Pacific. Aferthe loss of the Marshalls, however, the Japanese pulled the Imperial Fleet out of Truk. The lst major vessels left the imposing naval base only days before extensive American air strikes began. This completed the isolation of Rabaul nd left the Marianas without a potentially important source of support. The Japanese left soldiers abd air assetts to fight it out with the Americans. Instead air strikes destroyed the air assetts. And the substantial garrison was left to starve. With out air and naval assetts, the Truk grison became essentially self-imposed POWs--but POWs without any means of feeding themselves.


Civilians on the Marshall Islands before the War were self suficent in food production. The population, however, was small and the agricultural land on these atols was very limited. They produced very little surplus. As the Japanese began craming soldiers and Korean workers on these atols, food became a critical problem. The island were not capable of producing food for thousands of additional people. The basic Japanese policy was for areas it occupied to become self suffient in food. This was a pipe dream for garrisons throughout the Pacific. As aesult, the Japanese military garrisons not obliterated by American invasions would be left starving. As conditions inevitably deteriorated on Kwajalein and other islands, the Japanese soldiers became harsher and more violent toward the Marshall Island civilians who they were convinced were spying for the Americans. [Higuchi] After the war, a U.S. Naval War Crimes court tried several Japanese naval officers on Kwajalein for war crimes committed elsewhere, but not on the Marshall Islands. At least one was condemned to death. Aftr the Korean labor brigades comoleted the first runway on Kwajalein, the Japanese public school was demolished. The Marshall islanders were forcibly resettled. The Japanese civil administration was moved to Namu Atoll. The Marshall Islanders were moved to live on the smaller islets and atols. This was done with considerable brutality and traumatized the peaceful Marshall Islanders. Apparently the Japanese civil authoities had dealt with the Islanders with generally correct behavior, This was not the case if the soldiets. Ssimilar events unfolded throughout the Marshalls. After the American invasions, the Marshall Islanders were allowed to return to their homes. Civil affairs officers made sure that food and clean warer was made availavle as well as medical care. schools were opend with teachers who had been taught by the missionaries. We are not sure what happened with the small number of Japanese civilian the Japanese resettled in the islands. We do not note the horrific incidents of suiside as reported later on Saipan and Okinawa. We are not sure why. We assume a camp was set up for them where their ned could be met. They were repatriated to Japan after the war.

The Marianas

Adm. King set out to win approval for a Central Pacifuc campaign which MacArthur opposed because it would drain off resources for his New Guinea/Philippines campaign. King had already won approval for the invasion of the Gilberts and Marshalls as part of Operation Cartwheel--the isolation of Rabaul. But what King and Nimitz wanted was the Marianas. He knew because of Ultra and the logic of naval and air strategy that the Japanese would commit their fleet to the defense of the Marrianas and the Pacific Fleet was now ready for a fleet action. And they were supported by Air Force commander Hap Arnold who saw the advantages of conducting a strategic bombing campaign against Japan from the Marrianas instead of China as had originally been planned. Nimitz was less willing than King to take on MacArthur and the Army. King flew to Honolulu for a major conference with MacArthurs staff and Nimitz and his staff (January 1944). There he met considerable resistance. He finally ordered Nimitz to use the Pacific Fleet to drive into the Central Pacific.

Post-War Developments

The United States, as the occupying power, entered into an agreement with the new United Nations to administer most of Micronesia, including the Marshall Islands, as the Trust Territory of the Pacific Islands (1947). The United States used the islands for the Pacific Proving Grounds to test nuclear weapons. There were 67 nuclear tests on various atolls. The first hydrogen (Fusiin) bomb, codenamed 'Mike', was tested at Enewetak (1952). Fuion weapons wre exponentilly more powerful than the fision weapons used to end the war.


Higuchi, Wakako. "Micronesia under the Japanese Administration: Interviews with Former South Sea Bureau and Military Officials." ( Guam: University of Guam, 1987).

Spennemann, Dirk H.R. "Mili Island, Mili Atoll: A brief overview of its WWII sites".


Navigate the CIH World WarII Section
[Return to Main World War II island territory page ]
[Return to Main World War II country page ]
[Return to Main Pacific War page]
[About Us]
[Aftermath] [Biographies] [Campaigns] [Children] [Countries] [Deciding factors] [Diplomacy] [Geo-political crisis] [Economics] [Home front] [Intelligence]
[POWs] [Resistance] [Race] [Refugees] [Technology] [Totalitarian powers]
[Bibliographies] [Contributions] [FAQs] [Images] [Links] [Registration] [Tools]
[Return to Main World War II page]
[Return to Main war essay page]
[Return to CIH Home page]

Created: 7:09 AM 9/26/2008
Last updated: 2:43 AM 12/25/2015