The Battle of Tarawa was fought on 20–23 November 1943 between the United States and Japan on Tarawa Atoll in the Gilbert Islands, now part of the Republic of Kiribati but then a Japanese-occupied British colony. The battle was part of Operation Galvanic, the U.S. invasion of the Gilberts, and ended in a decisive American victory. Nearly 6,400 Japanese, Koreans, and Americans died during the battle, mostly on and around the small island of Betio, in the extreme southwest of Tarawa Atoll. At the time, Betio was only 118 hectares (290 acres).
The Battle of Tarawa was the first American offensive in the critical Central Pacific region. It was also the first time in the Pacific War that the United States faced serious Japanese opposition to an amphibious landing. Previous landings had met little to no initial resistance, but on Tarawa the 4,500 Japanese defenders were well supplied and well prepared, and they fought almost to the last man, exacting a heavy toll on the United States Marine Corps.
Background
American strategic decisions
To set up forward air bases capable of supporting operations across the Central Pacific, to the Philippines, and toward Japan itself, the U.S. planned to take the Mariana Islands. The Marianas were heavily defended. Naval doctrine of the time held that in order for amphibious landings to succeed, land-based aircraft would be required to weaken defenses and protect the invasion forces on the islands being invaded. The nearest islands capable of supporting such an American effort on the Marianas were the Marshall Islands. Taking the Marshalls would provide the base needed to launch an offensive on the Marianas, but the Marshalls were cut off from direct communications with Hawaii by a Japanese garrison and air base on the small island of Betio, on the western side of the atoll of Tarawa in the Gilbert Islands. Thus, in order to eventually launch an invasion of the Marianas, American strategists believed that the Japanese garrison and airfield on Tarawa would first need to be neutralized.
Following the completion of the Guadalcanal campaign, the 2nd Marine Division had been withdrawn to New Zealand for rest and recuperation. Losses were replaced, and the men were given a chance to recover from malaria and other illnesses that had weakened them during the fighting in the Solomons. On 20 July 1943, the Joint Chiefs of Staff directed Admiral Chester W. Nimitz to prepare plans for an offensive operation in the Gilbert Islands. In August, Admiral Raymond A. Spruance flew to New Zealand to meet with the new commander of the 2nd Marine Division, General Julian C. Smith, and initiate the planning of the invasion with the division's commanders.
Japanese preparations
Located about 2,400 miles (3,900 km) southwest of Pearl Harbor, Betio is the largest island in the Tarawa Atoll. The small, flat island lies at the southernmost reach of the lagoon and was the base of the majority of the Japanese troops. Shaped roughly like a long, thin triangle, the tiny island is approximately 2 miles (3.2 km) long. It is narrow, being only 800 yards (730 m) wide at its widest point. A long pier was constructed jutting out from the north shore, onto which cargo ships could unload while anchored beyond the 500-metre (550 yd)-wide shallow reef which surrounded the island. The northern coast of the island faces into the lagoon, while the southern and western sides face the deep waters of the open ocean.
Following Colonel Evans Carlson's diversionary raid on Makin Island in August 1942, the Japanese command was made aware of the vulnerability and strategic significance of the Gilbert Islands. The 6th Yokosuka Special Naval Landing Force reinforced the island in February 1943. In command was Rear Admiral Tomonari Saichirō (友成 佐市郎), an experienced engineer who directed the construction of the sophisticated defensive structures on Betio. Upon their arrival, the 6th Yokosuka became a garrison force, and the unit's identification was changed to the 3rd Special Base Defense Force. Tomonari's primary goal in the Japanese defensive scheme was to stop the attackers in the water or pin them on the beaches. A tremendous number of pillboxes and firing pits were constructed, with excellent fields of fire over the water and sandy shore. In the interior of the island was the command post and several large shelters designed to protect defenders from air attack and bombardment. The island's defenses were not set up for a battle in depth across the interior. The interior structures were large and vented but did not have firing ports. Defenders were limited to firing from the doorways.
The Japanese worked intensively for nearly a year to fortify the island. To aid the garrison in the construction of the defenses, the 1,247 men of the 111th Pioneers, similar to the Seabees of the U.S. Navy, along with the 970 men of the Fourth Fleet's construction battalion, were brought in. Approximately 1,200 of the men in these two groups were Korean laborers.
The garrison was made up of forces of the Imperial Japanese Navy. The Special Naval Landing Force was the marine component of the IJN and were known by U.S. intelligence to be more highly trained, better disciplined, more tenacious and to have better small unit leadership than comparable units of the Imperial Japanese Army. The 3rd Special Base Defense Force assigned to Tarawa had a strength of 1,112 men. They were reinforced by the 7th Sasebo Special Naval Landing Force, with a strength of 1,497 men. It was commanded by Commander Takeo Sugai. This unit was bolstered by 14 Type 95 light tanks under the command of Ensign Ohtani.
A series of 14 coastal defense guns, including four large Vickers 8-inch guns purchased during the Russo-Japanese War from the British, were secured in concrete bunkers around the island to guard the open water approaches. It was thought these big guns would make it very difficult for a landing force to enter the lagoon and attack the island from the north side. The island had 500 pillboxes or "stockades" built from logs and sand, many of which were reinforced with cement. Forty artillery pieces were scattered around the island in various reinforced firing pits. An airfield was cut into the bush straight down the center of the island. Trenches connected all points of the island, allowing troops to move under cover when necessary to wherever they were needed. As the command believed their coastal guns would protect the approaches into the lagoon, an attack on the island was anticipated to come from the open waters of the western or southern beaches. Rear Admiral Keiji Shibazaki, an experienced combat officer from the campaigns in China, relieved Tomonari on 20 July 1943 in anticipation of the coming fight. Shibazaki continued the defensive preparations right up to the day of the invasion. He encouraged his troops, saying "it would take one million men one hundred years" to conquer Tarawa.
Opposing forces
American
Naval forces
United States Fifth Fleet
Admiral Raymond A. Spruance in heavy cruiser Indianapolis
Ground forces
V Amphibious Corps
Major General Holland M. "Howlin' Mad" Smith, USMC
Japanese
Gilbert Islands defense forces
Rear Adm. Keiji Shibasaki (KIA 20 Nov)
Approx. 5,000 total men under arms
Battle
20 November
The American invasion force to the Gilberts was the largest yet assembled for a single operation in the Pacific, consisting of 17 aircraft carriers (6 fleet aircraft carriers, 5 light aircraft carriers, and 6 escort carriers), 12 battleships, 8 heavy cruisers, 4 light cruisers, 66 destroyers, and 36 transport ships. On board the transports were the 2nd Marine Division and the Army's 27th Infantry Division, for a total of about 35,000 troops.
As the invasion flotilla hove to in the predawn hours, the island's four 8-inch guns opened fire. A gunnery duel developed as the main batteries on the battleships USS Colorado and USS Maryland commenced counter-battery fire. This proved effective, with several of the 16-inch shells finding their marks. One shell penetrated the ammunition storage for one of the guns, setting off a huge explosion as the ordnance went up in a massive fireball. Three of the four guns were knocked out in short order. One continued its intermittent, though inaccurate, fire through the second day. The damage to the big guns left the approach to the lagoon open.
Following the gunnery duel and an air attack of the island at 06:10, the naval bombardment of the island began in earnest and was sustained for the next three hours. At least 40% of defenders were killed during the naval bombardment before H-hour. Two minesweepers, with two destroyers to provide covering fire, entered the lagoon in the pre-dawn hours and cleared the shallows of mines. A guide light from one of the minesweepers then guided the landing craft into the lagoon, where they awaited the end of the bombardment. The plan was to land Marines on the north beaches, divided into three sections: Red Beach 1 on the far west of the island, Red Beach 2 in the center just west of the pier, and Red Beach 3 to the east of the pier. Green Beach was a contingency landing beach on the western shoreline and was used for landings on 21 November. Black Beaches 1 and 2 made up the southern shore of the island and were not used. The airstrip, running roughly east–west, divided the island into north and south.
Marine Corps battle planners had expected the normal rising tide to provide a water depth of 5 feet (1.5 m) over the reef, allowing their 4-foot (1.2 m) draft Higgins boats room to spare. However, on this day and the next, the ocean experienced a neap tide and failed to rise. In the words of some observers, "the ocean just sat there", leaving a mean depth of 3 feet (0.9 m) over the reef. A New Zealand Army liaison officer, Major Frank Holland, had 15 years' experience on Tarawa and warned that there would be at most 3 feet depth. Colonel David M. Shoup, commander of the 2nd Marine Regiment, warned his Marines that there would be a 50–50 chance that they would need to wade ashore, but the attack was not delayed until more favorable spring tides.
The supporting naval bombardment lifted, and the Marines started their attack from the lagoon at 09:00, thirty minutes later than expected, but found the tide had not risen enough to allow their shallow draft Higgins boats to clear the reef. Only the tracked LVT "Alligators" were able to get across. With the pause in the naval bombardment, those Japanese who had survived the shelling were again able to man their firing pits. Japanese troops from the southern beaches were shifted up to the northern beaches. As the LVTs made their way over the reef and into the shallows, the number of Japanese troops in the firing pits slowly began to increase, and the volume of combined arms fire the LVTs faced gradually intensified. The LVTs had holes punched through their non-armored hulls, and many were knocked out of the battle. Those LVTs that did make it in proved unable to clear the sea wall, leaving the men in the first assault waves pinned down against the log wall along the beach. Several LVTs went back out to the reef in an attempt to carry in the men who were stuck there, but most of these were too badly holed to remain seaworthy, leaving the Marines stuck on the reef some 500 yards (460 m) off shore. Half of the LVTs were knocked out of action by the end of the first day.
Colonel Shoup was the senior officer of the landed forces, and he assumed command of all landed Marines upon getting ashore. Although wounded by an exploding shell soon after landing at the pier, Shoup had the pier cleared of Japanese snipers and rallied the first wave of Marines who had become pinned down behind the limited protection of the sea wall. Over the next two days, working without rest and under constant withering enemy fire, he directed attacks against strongly defended Japanese positions, pushing forward despite daunting defensive obstructions and heavy fire. Throughout, Shoup was repeatedly exposed to Japanese small arms and artillery fire, inspiring the forces under his command. For his actions on Betio, he was awarded the Medal of Honor.