Even before the United States entered World War II, American President Franklin Roosevelt met with British Prime Minister Winston Churchill in August 1941 at a secret conference off the coast of Canada. At this Atlantic Conference, the two decided that no matter who should join the Axis powers, the primary enemy was Germany and all planning should take place with that in mind. The policy of “Germany first” would be sorely tested when Japanese aircraft bombed Pearl Harbor in December 1941 and the United States became a full participant in the war.
As Japanese forces expanded through Southeast Asia and the Central and South Pacific, American planners began to call for more and more supplies and manpower to be diverted to the war against Japan. The postponement of a proposed invasion of France from 1943 to 1944 allowed the redistribution of American forces to the Pacific. In Washington and in the Pacific theater, however, there was little agreement on how those forces should be deployed. American General Douglas MacArthur was based in Australia after the successful Japanese invasion of the Philippines. He had promised the people of the Philippines that he would return to liberate them, and his plans were designed toward that end. But U.S. Navy leaders did not want to turn their ships over to army command or risk them in the distant waters of the Southwest Pacific. Admiral Chester Nimitz, commanding the Pacific Fleet, with the support of Chief of Naval Operations Admiral Ernest King, preferred a plan that had been developed prior to the war. Plan Orange called for action across the Central Pacific toward the Philippines. Neither King nor MacArthur seemed to concede much to the “Germany first” plan and, in planning conferences held with the Americans, the British continued to press for fewer troops to the Pacific in favor of operations in Europe.
MacArthur had a prestigious career and many friends in Washington, but he could not directly influence decisions there as long as he stayed in Australia. Thus, he had to demand as much as he could and hope for the best. Because of the navy’s resistance to the idea of committing too many valuable aircraft carriers to support army operations, someone had to make the decision, and it fell to the Joint Chiefs of Staff in Washington. With a modicum of navy support, MacArthur would direct the operations of American, Australian, and New Zealand forces in the Southwest Pacific with the primary aim of regaining control of New Guinea and the Japanese-held Solomon Islands to the east. The U.S. Navy, with its Marine Corps, would go through the Central Pacific.
Before the war and after their conquests in the first six months of the war, the Japanese had fortified islands virtually too numerous to mention. Recapturing every island would be an overwhelming task, so the navy planners decided that many could be bypassed and cut off, saving valuable time and manpower. By this strategy, some of Japan’s most powerful bases would prove utterly useless to them. American forces would need only to capture key islands with good airfields or anchorages in order to control an area. With the expanding U.S. submarine fleet and air superiority established with carrier-based and then island-based planes, Japanese strongholds would be denied reinforcements or supplies. Regular bombing would destroy their air forces and runways, so the strongholds would be neutralized and unable to impede American progress or assist the Japanese war effort.
The Solomon Islands
The first American offensive operation against Japan was against the island of Guadalcanal in the Solomons on 7 August 1942. The Japanese were unprepared for the landings, and U.S. Marines gained a quick beachhead. The Japanese responded with a vengeance, and the Americans learned for the first time of the tenacity and aggressiveness of the Japanese soldier. Whatever lessons army forces may have learned when the Philippines fell went unheeded, so the Marines had to deal with an enemy of unexpected ferocity. The Japanese military were trained under a strict code of conduct, the ancient Bushido warrior’s code, which taught that victory was everything and surrender was not an option. Unlike troops of virtually every nation in the world, Japanese forces would not admit defeat, and fought to the death in every engagement. Prisoners were few and far between.
The struggle for Guadalcanal was one of the longest in the Pacific war. The Japanese scored an early naval victory, which forced the United States to withdraw its support of the Marines on the island. The Japanese regularly brought in reinforcements from bases farther up the Solomon chain, and used their navy to pound American positions. Ultimately, the Americans won with a stubborn air defense and an even more stubborn force of Marines, and the island was declared secure in February 1943. Fighting in jungle conditions was a new experience for Americans, but it continued in the other battles in the Solomons. In July 1943, Marines assaulted New Georgia, northwestward up the chain, and on 1 November, the largest island, Bougainville. By Christmas, most of the airfields were captured, and by mid-January 1943, the invading marine forces were relieved by army occupation forces to finish the job. Christmas landings also took place on New Britain, home of the largest Japanese base in the Southwest Pacific, Rabaul. Three months of fighting in the jungles brought American conquest of only a third of the island, but with airfields in hand they could pound Japanese defenses and isolate the garrison. MacArthur continued his offensive by securing New Guinea, which put him in a position to plan for his return to the Philippines.
The Gilbert and Marshall Islands
As the Marines moved up the Solomons, Admiral Nimitz got his Central Pacific campaign under way. The first target was Tarawa Atoll in the Gilbert Islands, northeast of the Solomons. The landing would be unlike anything the Americans had ever attempted, since this was a small collection of coral islets surrounded by reef. The Japanese had approximately 4,800 men defending Betio, three miles long and no more than 600 yards wide. Betio was the site of the airfield, so this was the target. The Japanese had spent a year building bunkers of concrete, palm logs, and sand so well constructed that only a direct hit by the largest naval shells could harm them. Every square foot of the beaches had been zeroed in by mortars and artillery.
The landing was preceded by a three-day naval bombardment, and the Marines were in trouble from the start. Most of the landing craft could not get past the reef, and the men had to wade 700 yards across a lagoon in water up to their necks under crisscrossing machine-gun fire. Those who managed to reach the beach found themselves under intense mortar fire and unable to advance because of a seawall. For most of the first day, 20 November 1943, they were pinned down, unable to advance or retreat. Once they broke through the seawall, the Marines had to reduce each bunker, one at a time, with explosive charges placed against the concrete and through the gunports. The interlocking Japanese fields of fire made each assault extremely difficult. Within 76 hours the Americans secured the island, though the short time period belies the adversity. Only 146 prisoners were taken, most of them Korean laborers. Virtually the entire Japanese garrison had to be killed, at a cost to the Marines of 1,000 dead and 2,000 wounded. Nearby Makin Island, another atoll in the Gilbert group, was easier to capture, costing the lives of another 66 soldiers while defeating more than 400 Japanese defenders.
The Tarawa landing became a proving ground for future amphibious operations. From now on, longer preinvasion bombardments would take place. The Marines who fought here, already veterans of jungle warfare at Guadalcanal, learned how to fight on coral sand with no cover, lessons that were put to good use shortly. A mixed marine and army force landed at Majuro and Kwajalein atolls in the Marshall Islands, north of the Gilberts. The Japanese had not been able to reinforce this island group because of heavy losses in other areas, and the Americans made fairly short work of this island chain. Landings began on 30 January 1944, and the largest island, Kwajalein (site of the world’s largest lagoon), was declared secured by 4 February. The Americans attacked Eniwetok, the westernmost atoll in the Marshalls, on 18 February, and the islands of the atoll were declared secured by 23 February. Control over the Gilberts and Marshalls gave the United States secure bases for the most difficult of operations to come: the Caroline Islands and the huge Japanese base at Truk. As it turned out, that invasion proved unnecessary. An American carrier raid against the harbor in February destroyed so many Japanese aircraft and ships that the bulk of the fleet stationed there was withdrawn farther west to the Palau Islands. Truk—indeed, the entire Caroline group—was bypassed.
The Mariana Islands
With the outer rim of Japanese defenses pierced or controlled, the inner ring came under attack in the summer of 1944. The Marianas contained fine harbors and airfields, and included Guam, an American possession since 1898 that was lost to the Japanese at the start of the war. Possession of islands here would put the U.S. Air Force within range of the Japanese home islands. Also, the connection between Japan and its bases in the Southwest Pacific would be severed. To avoid this, the Japanese prepared for a huge naval battle, which they were confident they could win if they could bring their capital ships into contact with the American fleet. The naval battle took place, but the tradition of Tsushima in the Russo-Japanese War, or even the surface victories off Guadalcanal, was not to be repeated. The aircraft carrier was the dominant player and, since Midway, the United States owned the advantage in these ships.
To avoid tipping his hand as to the location of the next strike, Nimitz used 15 aircraft carriers to strike everywhere at once. They supported MacArthur’s landings on the north coast of New Guinea, struck Truk again, and then struck the Palaus. The carriers hit targets at Saipan and Guam in the Marianas and made a side trip to Iwo Jima, halfway to Japan, to interdict any reinforcements from the home islands. Saipan was a target of the first landings on 15 June 1944. When the landings began, the Japanese imperial navy knew just where the American fleet was, and they gathered their strength for the major clash they envisioned.
What ensued—later called the Battle of the Philippine Sea—became more popularly known as the “Marianas Turkey Shoot.” Rather than leave the landing force unprotected, U.S. Admiral Raymond Spruance stayed near Saipan and waited for the Japanese fleet to come to him. With advance warning provided by submarines, the Americans were prepared to protect their ships with swarms of fighter aircraft when Japanese bombers and fighters arrived on 19 June. Of the 430 planes onboard his five heavy and four light carriers, Japanese Admiral Oiawa lost 328 on the first day and 75 on the second. Two Japanese carriers were sunk by American submarines; another was sunk and two damaged by American aircraft. These losses, plus the damaging of a battleship and cruiser, forced the Japanese to withdraw. The Japanese navy was now in tatters.
Meanwhile, the Marines and soldiers on Saipan were victorious as well. The island was declared secured on 7 July, and the island of Tinian, just south of it, was invaded 24 July and secured on 1 August. Landings on Guam, at the southern end of the island chain, took place on 21 July, and the island was totally in American hands by 10 August. Now the long-range B-29 bombers had a base from which to begin the strategic bombing of Japanese cities.
Iwo Jima and Okinawa
MacArthur returned to the Philippines in October 1944 after the Marines had occupied Peleliu, the main island in the Palau group southwest of Guam and due east of the Philippines. These islands acted as a staging area for MacArthur. As American forces fought to regain the Philippines through the end of 1944 and the first months of 1945, Nimitz and the navy prepared plans for another offensive.
The air force had been losing a significant number of damaged aircraft returning from raids on Japan, and the high command decided that possession of Iwo Jima, due south of Japan, would allow the crippled bombers to land and save large numbers of aircrew. Accordingly, the invasion began in February 1945. Iwo Jima was a volcanic island covered with sulfurous ash. The Japanese had had years to dig in, and their time had not been wasted. More than 20,000 Japanese who garrisoned the island were often entrenched in caves where naval gunfire could not reach. When the Marines landed to light resistance, they hoped for an easy time, but instead they saw a replay of Tarawa in the accurate, predetermined targeting by Japanese artillery. The rugged terrain and entrenched enemy conspired to make this the Marines’ most deadly operation to date. It took five weeks to secure the island and months to flush out the last Japanese defenders. Ultimately, it took more than 6,000 dead and 18,000 American wounded to defeat the Japanese garrison, who fought as ardently as their comrades on every other island. More than 2,400 damaged B-29s landed here, saving many thousands more lives than were lost in the battle.
The invasion of Okinawa, scheduled for 1 April 1945, was a preview of the invasion of Japan itself. Okinawa had long been a Japanese province, and its inhabitants were officially Japanese citizens. Fighting here would give the Allied high command a taste of what it would be like to fight Japanese civilian resistance. Further, they expected a hard-fought struggle for the first territory of Japan proper.
They got what they were looking for. Many civilians either fought the Americans or committed suicide rather than become prisoners, believing the propaganda they had heard concerning American atrocities. Most of the fighting took place on the southern half of the island, a honeycomb of caves that had to be cleared one at a time. The Japanese garrison of 117,000 fought to the finish, the resistance lasting through July. The Japanese tactic of kamikazes, suicide aircraft attacks against American shipping, which had been introduced in the Philippines, proved to be a major headache for the U.S. Navy. They lost 34 ships sunk and more than 350 damaged, but it was not sufficient to turn them away.
The capture of Okinawa put the United States (plus the Allied forces of Britain and the Soviet Union once Germany was defeated in May) in a position to invade Japan. Plans were under way for a November invasion, but it never came about. President Harry Truman’s decision to use newly developed nuclear weapons brought the war to an abrupt end. The island-hopping campaign demonstrated the ability of amphibious troops to land and overcome any prepared defenses, provided reinforcements and naval support were sufficient. Lessons learned here would be repeated again in just five years, when MacArthur again ordered Marines to go ashore at Inchon during the Korean War.
See also: Japan, Planned United States’ Invasion of; MacArthur, Douglas; Manchuria, Japanese Invasion of (1904) (Russo-Japanese War); Midway, Japanese Invasion of; New Guinea, Japanese Invasion of; Philippines, Japanese Invasion of the; Philippines, U.S. Invasion of the; South Korea, North Korean Invasion of (Korean War).
References:
Dunnigan, James, and Albert Nofi, Victory at Sea (New York: Morrow, 1995); Leckie, Robert, Strong Men Armed (New York: Random House, 1962); Morrison, Samuel E., The Two-Ocean War (New York: Little, Brown, 1963).