On 15 September 1944, the 1st Marine Division assaulted the beaches of Peleliu. During this battle, Japanese forces on the island conducted one of the largest armored counterattacks of the war in the Pacific. The Japanese had established a counterattack team using light tanks as the main force. The ultimate plan of the counterattack force was to destroy the American forces while on the beach. The Japanese waited too long to conduct the counterattack. The Marines had quickly established the beachhead and developed hasty defensive positions with tank support prior to the initiation of the Japanese attack. The inability of the Japanese to properly coordinate the attack contributed to its failure.
The Marines’ amphibious assault plan was designed to get tanks onto the beach early in the attack. They adopted the organization of one tank battalion consisting of fifty- six tanks for every Marine division. During the battle of Peleliu, the Marines placed thirty tanks in the fourth wave. One tank platoon was attached to each infantry battalion for the operation.
During the battle for Peleliu, the tank’s primary role during the assault was to provide fire support for the infantry. Initially, tanks supported from just behind the infantry and were brought forward as needed. They were used to reduce Japanese strongpoints by using their thick frontal armor to get close to fortifications and fire point blank into enemy positions. The tactic of using armor in direct support of infantry continued throughout the day until the Japanese began a counterattack at approximately 1600 hours.
The Japanese tank-infantry counterattack was well-designed but poorly timed and executed. The attack was conducted across an open beach area in which the fast-moving Japanese tanks quickly outdistanced their infantry support. The American tanks, in strong, defensive positions, had clear fields of fire at the attacking enemy. Japanese infantry riding on the tanks were easy targets for Marine infantry firing from their foxholes. By 1730 hours, the Japanese had lost thirteen tanks to American tank and antitank fires and the counterattack failed. Had the attack occurred prior to the Marines’ consolidation on the beach and the arrival of the tank forces, the result could have possibly favored the Japanese.
Lessons learned during the battle of Peleliu included the effectiveness of infantry and tank forces working as a combined arms team. The infantry would protect the tanks from enemy infantry and clear the route of march of mines and obstacles while the tanks provided direct fire support for the infantry during assaults. On one coastal flat plain on the island, tanks conducted armored reconnaissance patrols ahead of the infantry. On determining the enemy’s location and strength, the infantry would conduct the assault while tanks provided support. The development of the tank-infantry team concept was expanded to the level where tanks were accompanied by infantry wherever physically possible, and many places where few thought it possible. Additionally, the use of engineer bulldozer support to build roads for tanks was paramount to the success of the operations.
During the early months of 1945, Allied forces continued the push toward Japan and on 18 February 1945 assaulted the island of Iwo Jima. Within the first hour- and-a-half of the assault, the Marines began to land tanks to support the infantry. The initial employment of tanks during the assault was the same as in previous battles. A small number of tanks, normally platoon size, were attached to an infantry battalion with the primary role of providing direct fire support to the infantry. Tanks were primarily used to destroy bypassed enemy bunkers, and flame thrower tanks were used to destroy enemy entrenchments which catacombed the sides of Mount Suribachi.
The initial problem to be overcome on Iwo Jima was one of mobility for the armored vehicles. The soft sand caused difficulty for the armored forces as they reached the beachhead. Many tanks became mired and thus easy targets for enemy antitank and indirect fire weapons. Additionally, the heavily mined beaches disabled five tanks in the initial wave. Out of necessity, the infantry and engineers had to clear the mines in order to get the tanks off the beach.
A Japanese strongpoint in the vicinity of Airfield Number 2 became the next major obstacle for the Marines. The Japanese had withstood many direct infantry assaults on their strong defensive position, which was a series of bunkers that covered the open area of the airfield. The Marines massed two battalions of armor and assaulted the enemy position with the infantry close behind. Additionally, indirect fire support was provided by ships located just off shore, artillery, and naval air. During the assault, several tanks were lost to enemy mines and direct fire weapons, but the remainder forced a deep penetration into the Japanese position which was quickly exploited by the infantry. This armored assault was one of the largest in the Pacific theater, but the tank force was severely depleted by the end of the battle. For example, the 3rd Tank Battalion landed 46 tanks on Iwo Jima, and lost 14 of them during this fight. For the remainder of the fighting for Iwo Jima, tanks operated in platoon-sized elements in direct support of the infantry.
During the Iwo Jima campaign, flamethrower tanks were used extensively against enemy pillboxes. The Japanese built their bunkers in low-profile or defilade manner, making them almost impervious to direct fire in many cases. The Marines used flamethrower tanks to destroy the bunkers. This required the tanks to maneuver to almost point blank range before they could adequately engage the target. In many cases, bulldozers were used to make roads for the tanks in order to reach the objective area. This movement of heavy equipment required the close coordination of infantry, engineers, and armor in order to protect all of the assets. Due to the success of the tank-engineer flame operations, the dozers soon became the focal point of enemy counterattacks.
The battle for Iwo Jima was costly in terms of American lives and equipment lost, but many lessons were reinforced in terms of the role of armor. The use of armor in small numbers in direct support of infantry became the rule and not the exception. The most effective employment was the tank-infantry team working in close coordination. Whenever possible, the tanks would lead to achieve limited objectives. The terrain most often dictated how far and how fast tanks could advance. When they were unable to lead, engineers were brought forward to clear the route while the infantry continued the attack. Flamethrower tanks were invaluable against caves and low-profile pillboxes which were difficult to hit with direct fire. The flamethrower tanks caused the enemy to flee their strong positions, making them easy targets for the infantry.
One of the last major and most costly battles in the Pacific began on 1 April 1945 with the assault landing of Marines on the island of Okinawa. Once again, armor was employed whenever possible in the same organizational structure that worked effectively in previous island battles: a small number of tanks in direct support of infantry operations. A different Japanese technique of employing obstacles in depth caused minor changes to the scheme of maneuver. Tanks, which previously most often led, were best used to support the infantry with both direct and indirect fires. Tanks continued to use their firepower and armor protection to get close to and destroy enemy bunkers, caves, and dug-in positions as the terrain would allow. Flamethrower tanks again were very effective in these types of engagements.
The coordination between the two combat arms (infantry and tanks) became highly acute during the campaign. The Japanese developed the concept of tank- destroyer teams which consisted of Japanese infantrymen who launched suicide assaults by strapping explosives to their bodies and running into the tanks, blowing up both themselves and the tanks. This required the infantry to provide close-in protection for tanks in order to prevent the suicide teams from succeeding. Tanks were also used to eliminate bypassed enemy forces on the beach after the infantry had cleared the area, and beachhead defense once the area was developed.
The battle for Okinawa was primarily an infantry action with tanks in a minor role. The tank-infantry team was used whenever the terrain and situation permitted. The main role of armor during the battle for Okinawa was to provide direct support to the infantry in whatever way possible. At times this included moving critical supplies to isolated infantry units who were unable to be resupplied by other means. It also meant using tanks to evacuate casualties from the battlefield as they returned to the beachhead to resupply. During the battle for Okinawa, both infantry and tank forces relied on each other for protection, mutual supportive fires, and to achieve the final objective: to close with and destroy the enemy.