The Marianas were unique in that they were divided beteen the United States and Japan before World War II. The Americans obrained Guam from Spain as a result of the Spanish-Aerican War (1898). The Japanese seized Sipan and Tinian from Germany during World war I (1914-18). Durng the inter-War era by international agreement, the islands were not to be fortified. The Japanese began to militaize their islands, the United States did not. Japan immediately after Pearl Harbor seized Guam which had only a small Marine detachment with small arms (Scember 1941). Later in the War, the Marianas became a major battlefield of the War. The Navy's Central Pacific campaign was unopposed by the Imperial Fleet. The Japanese hoped that fortified islands could resist amphibious invasions without the Fleet intervening. After the Ameicans took the Marshalls, Gilberts, and Carolines, it was clear that they could not. For the Japanese the stakes were very high. The Marianas brought the Japanese Home Islands within range of the new B-29 bombers. So when the American landings on the Marianas began, the Imperail Fleet did intervene, setting up one of the climatic battles of the Pacific War--the Battle of the Phillipine Sea (1944). As the Marine and Army troops were going ashore, the B-29 bombers were coming off the assembly line at American aircraft plants.
The Marianas is an important Micronesia archepeligo in the central Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east. The Northern Marianas consists of 14 tropical islands stretching across 400 miles. They are adjacent to the Marianas trench which is the deepest point in the ocean. The islands are volcanic formations, in fact the summits of volcanic mountains in the north-western Pacific. Saipan is the most populated island in the group. Tinian is a smaller island near Saipan. Rota to the south is much less developed. The southern-most island is Guam. The war developed somewhat differently on the islands because Guam was separated from what became known as the Northern Marianasa (Rota, Saipan, and Tinian). The other islands are much smaller and of lesser importance.
The Marianas is an important archepeligo in rhe central Pacific. The Northern Marianas consists of 14 tropical islands stretching across 400 miles. They are adjacent to the Marianas trench which is the deepest point in the ocean. Saipan is the most populated island in the group. Rota is much less developed. The Northern Marianas were settled around 1500 BC by Chamorros who have cultural ties with the indigenous people on Guam. Ferdinand Magellan was the first European to discover the islands (1521). He named them the Islas de los Ladrones (Islands of Thieves) because of his experiences with the Chamoros. Spanish Jesuit Luis Diego Sanvitores renamed the islands Las Marianas in honor of the Spanish queen Maria Ana of Austria (1668). He and five other priests established a mission in the Marianas. The Spanish effort to Christanize and control the islands set off two decades of often brutal hostilities between the Spanish and the Chamorros who violently resisted them. The Spanish had to commit a substantial military force to gain control of the islands. Because of lingering resistance, the Spanish rounded up most of the the Chamoros on Saipan and trasported them to Guam. The Spanish had more trouble doing this on Rota where most of the Chamoros managed to hide in the island's caves and mountains. The Spanish permitted Caroline islabders to move to Marianas where they tended cattle for the Spanish. Pope Leo XIII confirmed Spanish sovereignty over the Marianas (1885). Spain began encouraging the Chamoros on Guam to move to the Northern Marianas. The Guam Chamoros were now throughly Hispanicized. The Spanish saw a larger Chanoro population on Saipan and other islands in the Northern Marianas as a way of strengthening Spanish control. The Carolinians had by that time settled much of the most productive coastal areas. The United States seized the Philippine Islands and Guam during the Spanish-American War (1898). The Spanisg decided that there was not benefit in having the Northern Marianasa. The decided to seel the islands to Germany. Kaiser Wilhelm II at the time was building a new high seas navy and anxious to acquire colonies. The Northern Marianas and other Pacific Islands acquired by the Germans provided useful facilities for the new German Navy. The Germans also hoped to develop copra production.
The Spanish American War was primarily fought over Cuba. Insurgents on Cuba had been fighting the Spanisg for decadeds. American newspapers picked up on the struggle and began running lurid articles about Spanish colonial opression. When the USS Maine blew up in Havana harbor, the newspapers blamed the Spanish. With the outbreak of war, the U.S. Navy engaged Spanish squadrons in both the Atlantic and Caribbean. The major Atlantic sea battle occurred off Santiago, Cuba. The United States also attacked Spanish possessions in the Pacific. This primarily meant the Philippine Islands. The U.S. Navy destroyed the Spanish Pacific squadron in Manila Bay. In the peace settlement, the Americans also obtained Guam. These possessions along with the annexation of the Hawaiian Islands made the United States a Pacific power.
Japan had a Naval Alliance with Britain. When World War I broke out in Europe, the Japanese entered the War on the Allied side. The British were at first surprised at the Japanese eagerness to enter the War. Japanese officials saw some advantages to be gained from the War, particularly the opportunity of seizing German colonies. This was helpful to the British because it allowed the Royal Navy to maintain only a small squadron in the Pacific to deal with the Germans. Japanese, British, and Dominion forces seized the German outposts. The World War I settlment assigned the northern colonies to Japan and the southern colonies to Australia. The Japanese thus acquired the Northern Marianas (Rota, Saipan and Tinian). The Ameicans continued to control Guam to the south. The islands were not to be fortified. The Japanese began to militaize their islands, the United States did not.
The Japanese saw the Northern Marianas as useful both militarily as well as an economic assett. The Marianas served as useful air and naval bases to build a shield around Japan. Economically the Japanese were particularly interested in sugar cane. They proceed in clearing groves of coconut palms planted by the Chomoros as well asand tropical forests. This included many ancient latte stones important to the Chamoros. Large numbers of Japanese civilians were brought in to develop the economy. This proved an economic success. The Marianas sugar cane operations were producing 60 percent of the revenues the Japanese were generated in Micronesia. The Japanese also changed the Northern Marianas demographically. When the Japanese acquired the islands, there were about 4,000 Chamorros. The Japanese population when the War began was 45,000, mostly immigrant workers. The Marianas thus became essentially Japanese islands. The Japanese recreated the islands amd thgus life there became similar to that on Japan itself. Schools were opened for the Japanese children.
Japan immediately after Pearl Harbor seized Guam which had only a small Marine detachment with small arms (December 1941). American authorities concluded based in part on decoded Japanese diplomatic messages that Japan was preparing to declare war and strike and American and British possessions in the Pacific. The military assessment was that the strike would come in the eastern Pacific and not Pearl Harbor which was considered too stringly defended. The Navy did not believe thar lightly defended Guam could be sucessfully defended if the Japanese struck, as was likely at the outbreak of war. Strong Japanese forces existed in the Nothern Marianas. The Navy began evacuating the civilian dependents of the American personnel OOctober 17). At the time of Pearl Harbor only one deoendant was left on the Guam. The Navy ordered Guam's military governor, US Navy Captain George J. McMillin, to destroy all classified materials except those vital for options (December 4). Cpt. McMillin did so (Devember 6). The following day the Japanese unexopectedly struck Peal Harbor, largely imobilizing the Pacific Fleet (December 7). This was the omly force capable of defending Guam. With their success at Pearl Harbor, the outcome on Guam was inevitable. The American defence was only 274 sailors and 153 marines along with 100 Chamorros of the Home Guard. There were no heavy weapons. Japananese air strikes began (December 8). A 5,500 man Japanese invasion force began landing at 2 am in the morning (December 10).
The Japanese renamed Guam "Omiya Jima". Unlike Saipan to the north, there was no Japanese population on Guam, but a substantial Chomoro population of about 22,000 suffered under the brutal Japanese occupation. Guam was the only American terruitory with civilians occupied by Japan during the War. The Japanese also occupied two Aleutian Islands (Attu and Kiska), but the civilians had been evacuated. Japan was administered by the Japanese military. In Sumay, which was the island's commercial center, all of the 2,000 residents were evicted from their homes. Some, however, were given permission to dismantle their homes The Chamorros wre forced to endured 32 months of Japanese occupation. Japanese occupation of Guam proved especially brutal, even by Japanese standards. There were various reasons for this. Not only were the Japanese occupying American territory, but the Chamorros remained loyal to the Americans. Some Chamorros had defied the Japanese and hid American sailors attempting to evade capture. The Japanese permitted a degree of religious practice and business activities. Children's attendance was mandatory at occupation era schools, but of 5,000 children attending pre-war American schools, only 600 Chamorro children attended the schools opened by the Japanese. [Palomo] There were, however, numerous attricities committed by both officers acting in official capcity and poorly supervised military personnel. There were grenade slaughters and rapes. The 29th Division of Japan's Kwantung Army set up concentration camps. The Japanese executed 600 Chamorro's for various infractions. Some were beheaded. The Japanese were incensed when they learned of the 3-year effort by Chamorro's to hide and care for U.S. Navy radioman George Tweed. Japanese brutality increased as they began to prepare for invasion. The Japanese conscripted Chamorros for forced labor to building defenses and runways. Others were put to slave labor in rice paddies. Rice paddied did not exist on Guam before the War, but the Japanese ocuupiers wanted rice to eat. So they set up paddies at Piti, Inarajan and Merizo. They forced the Chamorros to work them. [Palomo] When American ships and planes appeared, Japanese barbarities on the Chamorros only escalated.
Japan seized German Pacific Islands during World War I and after the War, the League of Nations approived mandates. Japan secretly constructed ocean fortresses in violation of its commitments to the League as a Mandate power. These islands and the surrounding oceean areas were forbidden territory to foreign ships.
Japanese strategists before the War discussed the huge numbers of Pacific Islands and thought that the American fleet could not possiblly penetrate the Pacific island barrier protected by the Imperial Navy. [Matsuo] And after Pearl Harbor, the Japanese added more islands to that barrier. The Japanese did not anticipate the complexity and material neeed to garrison and supply all those islad fortresses or that the Unites States Navy could cut off those garisons and render them impotent by air attack. This greatly reduced the number that had to be invaded. Thus large numbers of Japanese garrisons spent the war cut off and by the end of the war were literally starving to death.
After the brusing Solomons naval campaign (August-Secember (1942), the Imperial Fleet withdrew from the South and Central Pacific. The Japanese fervently worked to launch new carriers and train pilots after the losses in the Coral Sea, Midwaty, and the Sollomons. At the same time large numbers of American ships and air crews began reaching the United States Pacific Fleet, fundamentall changing the naval ballance in the Central Pacific.
The Japanese has hoped that well-entrenched island garrisons in the Central Pavific could repell American an amphibious invasion without the need of naval support. American Marines in the Marshalls and Gilberts proved that they coud not. The Japanese were shocked at how rapidly after the successes in the South Pacoific, the Americans penetrated their outer island barrier.
The Marianas campaign was thus a major turning point in the Pacific War. The Japanese for the first time since the Solomons campaign committed the Imperial fleet's carriers. The Japanese High Command considered the Marianas crucial because they knew of the B-29s and air bases on the Marianas would bring the Home Islands within range of the new bombers.
Strengthening forces on the Marianas was complicated by shipping shortages. Japasnes new South Pacific Empire put a great strain on the Japanese nerchant marine from the very beginning of the War, but in 1943 the U.S. Mavy had solved its torpedo problem and had begun to sink large numbers of merchant ships. And as a result, by 1944 the merchant marine had been substantially reduced. Japanese preparations for defending the Marianas wee disrupted by the attempt to take back Biak, but before Biak could be retaken, the Ameeican invasion fleet appeared off Saipan.
The basic plan of the Japanese was to launch another devestating carrier strike against the American carriers. And the Japanese carriers would be supported by land based planes on Saipan and Guam. It was an ilconceived plan. Radio communications between the forces on the island were poor and in any case the Ameerican carriers desroyed the air foirces on the islands before the Japanese carriers could reach the American fleet. In addition, the Japanese carrier force was still using the same Mitsubishu Zeros while the Americans were using the new Hellcat fighters. But most important of all wasthat despite a year ad a half to prepare, the Japanese pilots were inexperienced and poorly trained. The Japanse battle plan took none of these factors in consideration.
Biak is an island in the Schouten Island Group off the northwestern coast of New Guinea which dominates the entrance to Geelvink Bay. It was 350 miles West of Hollandia, the major American base in New Guinea. The Americans and Australians by early 1944 had fought their way up the northern coast of New Guinea, destroying or isolating Japanese garisoins. General MacArthur could now begin to consider the invasion of the Philippines. Biak was the last major Japanese obstacle to securing New Guinea. The Japanese has suffered defeat after defeat in New Guinea. Japanese planners hoped that an island could be better defended and built up forces on Biak to about 11,000 men. The Americas landed 12,000 men on Biak (May 27). Colonel Kuzume Naoyuki decides not to oppose the beach invasion, but to make a stand inland at the airfield. General MacArthur tells the press, "... this marks the strategic end of the New Guinea campaign'. This proves to be premature. The first U.S. armoured battle of the Pacific war occured on Biak where six tanks fight it out (May 29). The Japanese garrison stuborn resistance managed to force the partial re-embarkation of U.S. forces. American forces finally take Mokmer airfield on Biak (June 7). The Japanese, however, continued to resist. The importance the Japanese gave to Biak can be seen by the fact that a major relief force was being readied supported by the Imperial Fleet. It is at this time that an American invasion fleet appeared off Saipan and the Imperial Fleet has to shift its attention to the new threat. Time and again in the Pacific War, the Japanese were thrown off ballance by having to contend with the two American drives, Nimitz in the Central Pacific and McArthur in the South Pacific.
The Marianas proved to be among the bloodiest battlegrounds of the Pacific War. The Navy's Central Pacific campaign was unopposed by the Imperial Fleet. The Japanese hoped that fortified islands could resist amphibious invasions without the Fleet intervening. After the Ameicans took the Marshalls, Gilberts, and reduced the Carolines by carrier strike, it was clear that they could not. For the Japanese the stakes were very high. The Marianasa were Closer to the Home Islands than the rest of Micronesia. The Islands were thus key to Japan's defensive perimeter and to the American Pacific strategy. The strategic bombing campaign was intially to be conducted from China. A japanese offensive there and the realization that the Marianasa would simplify the supply problem changed that. The Marianas brought the Japanese Home Islands within range of the new B-29 bombers. So when the American landings on the Marianas began with the invasion of Saipan, the Imperail Fleet did intervene, setting up one of the climatic battles of the Pacific War--the Battle of the Phillipine Sea (1944). The Japanese fleet air arm was destroyed as a capable force. After the defeat of the Imperial Fleet carriers and the fighting on Saipan reached the mopping up phase, the United States invaded Guam (July 20). The fierce fighting on Saipan and Guam resulted in nearly 40,000 killed. The Japanese garisons fought to the death and many of the civilias committed syuiside.
The Japanese invasion of China affected counless civilians as the Japanese noved south and into the inrerar from coastal areas. The same was the case of the subsequent incasion of Southeast Asia and the Dutch East Indies. The Pacific War was, however, very different. It was fought over a large number of small islands with very limited populations, in some cases uninhabited islands and atols. This began to change United states forces penetrated the outer perimiter of the Japanese defenses in the South and Central Pacific. The first substabtial civiliajn popularion encountered by American forces was in the Marianas. This included both indigenous people and Japanese colonists. These were the first Japanese civilians encountetred by American forces. The civilian population and compposition of the population varied from island to island, in part because the Americns contrilled the southern-most island--Guam. The Japanese as a result of World War I controlled the rest of the Marianas. The indigenous population was the Chamoros who the Japanese did nor trust. The Japanese settled large numbers of their own people on the islands in the inter-Ear era (1920s-30s). They founded a sugar industry to replace imports. As a result, at the time of the invasions, there were many Japanese civilians on Saipan and Tinian as well as Taiwanese and Koreans. The Chamoro population continued to be most impoerat on Guam. was promarily on Guam. A Census conducted in 1939 by the Japanese reported that the Japanese, Taiwanese, and Korean civilian population totaled 77,000, outnumbering the Chamorros (52,000). The Chamorros welcomed the Americans. The Japanese had a very different view which led to a tragedy, especially on Saipan. The Americans landed in the south and fought their way north. The Japanese retreated northward. Finally there was no where left. Lt. Gen Yoshitsugu Saito commanded the Japanese forces on the island. Saito ordered made plans for a final suicidal banzai charge (July 7). The Japanese civilians were terrified of the americans. Actuallt the greatest danger came from theor own soldiers. As for the civilians, Saito explained that death was the only answer. He explained, as to the fate of the surviving civilians on the island, Saito said, "There is no longer any distinction between civilians and troops. It would be better for them to join in the attack with bamboo spears than be captured." The attack began at dawn. led by group of 12 men carrying a great red flag. All the reamining able-bodied troops, some 3,000 men, charged with them. They were followed by the bandaged and bleeding walking wounded as well a some men on crutches. Amazingly, behind them came the wounded, with bandaged heads, crutches, and barely armed civilians.
It was the by the largest Japanese Banzai attack in the Pacific War. [Goldberg, pp. 167–94.] The Japanese broke into the American lines and hand to hand fighting insued. Some 630 Americanse killed or wounded. Almost all of the remaining Jpnese garrison, some 4,300 Japanese were killed. In the wake of this, the civilians began committing uiiside.
Following orders from Tokyo, Sito and othef Japanese commanders on Saipan ordered the Japanese civilians to commit suicide and thousands proceeded to commit mass suiside, determined to avoid capture by the Americans. Men who did not have weapons dove off the steep cliffs into shark-infested waters. Mothers imcredibly threw their babies against rock walls before jumping to their death. Some mothers jumped with babes in arms. Even children committed suicide. Some civilians had grenades, blowing themselves up in caves or jumping with them. This ws ofdten done in view of the advancing Americns who used their translators amd loud speakers to prevent the suisides. Some 8,000 civilians on Saipan died in this manner. The Americans were able to convince many people to surrender. The two sites of mass suiside became known as Banzai and Suicide Cliffs as memorial to these fallen civilians. Some 22,000 civilians died on Saipan. A large portion of that number were the mass suicides, civilans convinced that the Americans treated captives barbarously. On Tinian, a small handful of civilians also committed suicide, but the carnage was on a smaller scale. The situatiin was different in Guam with fewer Jaoanese and more Chamoros. Camps were set up for the Japanese, Only a handful of soldiers survived, but thoousands of terrified civilans did so, any in terribke condition. They were returned to Japan after the War.
As the Marine and Army troops were going ashore, the B-29 bombers were coming off the assembly line at American aircraft plants. The U.S. Navy Central Pacifiv campaign solved the baseing and supply problems for the U.S. Arny Air Forces. The seizure of the Marianas opened new possibilities for the strategic bombing campaign (June-July 1944). The islands (Guam, Saipan, Tinian) provided sites for airfields that were within range of the Home Islands. And not originally planned for strategic bombing campaign, the Marianas sloved the strategic and logistical nighmare fced in China. It was a lot easier to seize an island, no matter how well garisoned than advance armies into central China and engage large Japanese forces. In addition, the Marianasa were a straight supply run from San Franciso and other West Coast ports, eliminating the logistical nightmare of getting the vast supplies needed to China. The Air Force rushed to complete the large airfields needed by the B-29s and to deploy the planes and crews to the islands. The Seebees set out building the extended air strips need while the fighting for the Islands were still underway. The Marianas were secure (August 1944). The Seebees built five major B-29 bases on the Marianas, two on Tinian and Guam and one on Saipan. Saipan was larger thab Tinian, but very mounnenous. Tinian was flat and perfectly suited for B-29 runways. Each of the bases accommodated a bomb wing made up of four bomb groups, giving a total of 180 B-29s per airfield. [Peacok, p. 87.]
The XXI Bomber Command became operational (October 1944). The first B-29s reached the Marianas from China (October 1944). The first small mission hit Truk. Strikes on the Home Island began (November 1944). The first mission was an attack on Tokyo with 111 B-29s (November 24). These early missions dropped their bombs from high altitudes. The results were disappointing. High altitude raids continued for the first two month of 1945 with little success. Finally LeMay began low altitude raids. This began with the shattering B-29 raid on Tokyo with 315 B-29 (March 10, 1945). Much of the city was destroyed (16 square miles) and more people were killed than either of the to atomic bomb raids. This was when the B-29s began bombing in earnest. The XXI Bomber Command executed 315 B-29 missions with over 26,000 sorties (meaning planes participating on a mission). This would mean on average more than 80 sorties or planes per mission. As there were missions with only a few planes, the actual number on a major mission was higher. Most of these missions were flown (March-July 1945). Calculating the missions flown earlier (June 1944-February 1945) disguises the intensity of the bombing that began in March 1945).
The bombing essentially destroyed industrial Japan (except for a few cities) and Japan's ability to sustain the Pacific War. It did not, however, destroy the immense stockpile of men and material that the Japanese moved into Kyushu to repel the planned American invasion. It did destroy the Japanese transportation system so even if they managed to repel the American invasion, the population would begin starving in Fall 1945.
. They dropped bombs from about 30,000 feet (10,000 m). The post-bombing assessment suggested that only about 10 percent of the bombs hit their targets. The 20th Air Force was reassigned to the XXI Bomber Command. Under the command of Curtis LeMay, they organized a much more effective bombing campaign. Flying from the Marianas (ptimarily Guam and Tinian) the B-29s were within range of the Home Islands and able to carry a full bomb loads. The campaign was given great priority. The Bomber Commands did not report to the theater commanders (MacArthur and Nimitz), but rather directly to the Joint Chiefs of Staff. At the peack of operation, they were placed under the U.S. Strategic Air Forces in the Pacific, commanded by General Carl Spaatz (March 1945). The Americans as in Europe tried daylight precision bombing using high explosive bombs. The results were ineffective. The hight winds over the Islands (the Jet Stream) disrupted the trajectory of bombs dropped from high alditude which meant that targets were not struck. The B-29 was built for high altitutude operations and this was preferred because it was above the effective height of Japanese air defenses.
General LeMay, commanding the XXI Bomber Command, decided to change tactics. He switched to low altitude raids (about 2,100 meters) dropping incendiary bombs. The lower altitude improved accuracy and the indendiaries meant that specific targets did not have to be accurately hit, they would be destroyed in the huge conflgratiins of Japanese cities. The speed of te B-29s proved suffucent to protect the raiders. The raids focused on the major urban centers of Tokyo, Nagoya, Osaka, and Kobe. The early raids using this method were only moderately successful, but results stradily improved. There were also daylight raids on particularly important targets. The bombing made most of the headlines. A less punlicized aspect of the Pacific strategic bombing campaign was the mining of Japanese ports and shipping routes -- Operation Starvation. B-29s began dropping mines (April 1945). By this time of the War,the american submarine campaign had largely destroyed Japan's Maru flet and few shipment were reaching Japan from the SRZ. American submarines found it dificult dangerous to operate in the East China Sea and Jaoanese coastal waters. The mines made it incresingly difficucult to transport food to citiesand move trrops and militry equipment. [Caldwell, p. 33.]
Guam, Saipan, and Tinian were heavily damaged during the fighting. Rota which was bypassed experienced only minor damage. The important sugar cane industry was desestated. The United Nations made the Marianas a department of the Trust Territory of the Pacific Islands (1947). The United States received the exclusive rights to administer the islands and to establish and maintain military bases.
Caldwell, Hamlin A., Jr., "Air Force Maritime Missions", United States Naval Institute Proceedings (October 1978).
Goldberg, Harold. D-Day in the Pacific: The Battle of Saipan (Indiana University Press, 2007).
Kinoaki Matsuo. The Three Power Alliance And The United States Japanese War Matsuo's book explained how Japan could win a Pacific war with the United States. He was an intelligence officer who served as a liaison between the Japanese Foreign Office and the Admiralty. He argued that the "... the United States will be obliged to exercise prudence and self-restraint toward Japan at least until 1945." He believed that it would take this long for America to build up amidabe military force.
Peacock, Lindsay. "Boeing B-29... First of the Superbombers, Part Two." Air International (August 1989), Vol. 37, No. 2, pp. 68–76, 87.
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