By Ivan Toth

The Battle of Tarawa is one of the shortest and bloodiest battles in the Pacific, fought from November 20 to 23, 1943. It took place on Tarawa Island, which was part of the Gilbert Islands. Approximately 6,400 Japanese, Koreans, and Americans were killed either in combat or from wounds, mostly on and around the small islet of Betio, located on the far southwest of Tarawa.

Great significance of the battle

This battle was also the first major American offensive in the critical Central Pacific region; here, for the first time, Americans faced a serious Japanese defense during a landing operation, unlike previous landings where they encountered little or almost no resistance. In the Battle of Tarawa, the Japanese had 4,500 well-prepared and well-supplied troops who fought nearly to the last man, inflicting heavy losses on the U.S. Marines. Americans had suffered similar casualties in other campaigns, such as the Battle of Guadalcanal, which took place between August 1942 and February 1943; the only difference was that the American losses, which were numerically the same as at Guadalcanal, occurred in just 76 hours of fighting, while at Guadalcanal they were spread over six months of battle.

Background of the Battle of Tarawa

In order to establish an air base that would support aircraft for operations throughout the central Pacific, the Philippines, and toward Japan, the United States planned to capture the Mariana Islands, which were well defended. Naval doctrine at the time held that, for an operation to succeed, the island’s defenses had to be weakened by bombardment to protect the invasion forces landing on the island. The nearest islands suitable for such an operation were the Marshall Islands, northeast of Guadalcanal. Seizing the Marshalls would enable the construction of bases needed for launching the offensive against the Marianas; this, however, was complicated by the fact that the Marshalls were cut off from direct communication with Hawaii by the Japanese garrison and air base on the small islet of Betio, located on the western side of Tarawa, part of the Gilbert Islands. Therefore, before any invasion of the Marianas, it was necessary to capture Tarawa.

After the Guadalcanal campaign, the 2nd Marine Division was sent to New Zealand to rest and recover. Losses in the units were made up with new men, while the veterans were given time to recover from malaria and other diseases that had afflicted them during the Solomon Islands campaign. On July 20, 1943, the Joint Chiefs of Staff ordered Admiral Chester Nimitz to prepare a plan for an offensive against the Gilberts; the following month, Admiral Raymond Spruance arrived in New Zealand to meet with the new commander of the 2nd Marine Division, General Julian C. Smith, and to begin planning the offensive with division commanders.

Some 3,900 kilometers southwest of Pearl Harbor lay Betio, the largest island of the Tarawa Atoll. At its southernmost point in the lagoon stood a Japanese military base. Following the example of General Evans Carlson’s surprise raid on Makin Atoll in August 1942, Japanese commanders became aware of their vulnerability and of the strategic importance of the Gilbert Islands. In February 1943, the 6th Yokosuka Special Naval Landing Force was brought in to strengthen the island’s defenses. Its commander was Rear Admiral Tomonari Saichiro, an experienced engineer who directed the construction of sophisticated defensive installations on Betio. Upon arrival, the 6th Yokosuka Naval Engineer Regiment became the island’s garrison force and was renamed the 3rd Special Base Defense Force.

Tomonari’s main objective in Japan’s defensive scheme was to stop the invasion forces while they were still in the water and pin them down on the beaches. A large number of bunkers and machine-gun nests were constructed, offering excellent fields of fire over the water and sandy beaches. In the island’s interior stood the command headquarters and many shelters designed to protect the defenders from air raids and artillery fire.

Japanese Defense Plan

The island’s defensive positions were not arranged for inland fighting. The interior of the island was large and wide but lacked machine-gun nests. The defenders were limited to frontal attacks from the entrance to the lagoon.

The Japanese worked tirelessly for nearly a year to fortify the island. To help the garrison strengthen its defenses, 1,247 men from the 111th Pioneer Unit (similar to the U.S. Navy’s “Seabees”), along with 970 men from the 4th Fleet Engineer Battalion, were brought in for assistance. About 1,200 of these men were Korean forced laborers.

The garrison consisted of forces from the Imperial Japanese Navy (IJN). The Naval Landing Force was the marine component of the IJN and was known to U.S. intelligence as a highly trained, disciplined, and vigilant unit, with small units often having better command structures than those of the Imperial Japanese Army. The 3rd Special Base Defense Force, assigned to defend Tarawa, numbered 1,112 men. They were reinforced by the 7th Sasebo Special Naval Landing Force, which had 1,497 men. This unit was further supported by 14 Type 95 light tanks under the command of Ensign Ohtani.

A line of 14 coastal defense guns, including four large 8-inch Vickers guns purchased from Great Britain during the Russo-Japanese War, was mounted in concrete bunkers around the island to guard approaches from the open sea. These heavy guns were expected to make it difficult for naval forces to land in the lagoon and launch an attack from the north side of the island. The island was also “peppered” with 500 fortified machine-gun and artillery positions, built from logs and sand, many reinforced with concrete. Forty artillery pieces were scattered across the island in fortified pits. Trenches connected all strongpoints, allowing troops to move from one position to another as needed. Since the command believed their coastal guns would protect the lagoon approaches, it was assumed that an enemy attack would come from the open sea on the western or southern beaches.

Rear Admiral Keiji Shibazaki, an experienced officer from the China campaigns, replaced Tomonari on July 20, 1943, in the midst of preparations for the coming battle. Shibazaki continued fortifying the island right up until the invasion began. He encouraged his men by telling them “it would take one million men and one hundred years to conquer Tarawa.”

Course of the Battle: November 20, 1943

A week before the landings, U.S. Navy aircraft began bombing the island, later joined by naval bombardments. Many bunkers were destroyed, along with the airfield and several hundred Japanese soldiers. American leadership underestimated the Japanese strength and believed the island would be taken within 24 hours.

The invasion force assembled for the Gilberts was the largest yet for a single Pacific operation: 17 aircraft carriers, 12 battleships, 8 heavy cruisers, 4 light cruisers, 66 destroyers, and 36 transports. Aboard the transports were the U.S. 2nd Marine Division and elements of the U.S. Army’s 27th Infantry Division, totaling 35,000 troops.

The attack began on November 20, 1943, with naval bombardment targeting Betio, the largest and main island. After the shelling, the first wave of Marines advanced under air cover. However, because of the low tide, Higgins landing craft were stranded about 500 meters from shore, forcing Marines to disembark and wade slowly across the deadly shallows under heavy fire. Few made it through. Most of the first wave was nearly wiped out, and U.S. commanders rushed reinforcements forward. Some Marines were killed in stranded vehicles that became easy targets for Japanese artillery, while others drowned under the weight of their heavy gear and ammunition. Only the LVT-1 Alligator amphibious tractors, thanks to their tracks, managed to cross the reef. Supported by reinforcements and tanks, the Marines managed by midday to capture the first Japanese defensive lines.

As the first day drew to a close, the Marines were running out of ammunition, water was scarce, and the sea was filled with sunken vehicles and dead Marines. Half of the amphibious vehicles had been destroyed, and countless Marines were dead or wounded. Japanese commander Keiji Shibazaki was killed on the first day, but his troops did not need new orders; they would not retreat, fighting to the death or committing suicide.

Korean workers during Battle of Tarawa

Around 1,500 Marines were pinned down at the edge of the beach. At that point, Colonel David Shoup landed on Betio. Taking command, he rallied the Marines to assault and capture the first Japanese positions. U.S. Navy fighters and bombers provided precision strikes, destroying and suppressing Japanese artillery and infantry. By the end of the first day, of the 5,000 Marines who had landed, 1,500 had become casualties—either killed or wounded and incapacitated.

Betio Island was divided into six sections. On the first day of the invasion, November 20, the Marines landed on beaches Red 1, Red 2, and Red 3. By nightfall, the Americans managed to land several 37mm anti-tank guns to defend against Japanese armor, as well as mortars and a few Sherman tanks. During the first night, the Japanese did not counterattack, partly due to Shibazaki’s death and also because communications had been severed (most telephone lines had been destroyed during the bombardment).

Ivan Toth is a distinguished Croatian lawyer and analyst of social affairs.