On this day in military history…
On 15 June 1944, American amphibious warfare entered a new and more demanding phase. The landing on Saipan by forces carried and supported by Task Force 52 was not simply another step in the island-hopping campaign. It was the beginning of the first major assault by United States amphibious power against a relatively large, heavily defended land mass in the Central Pacific. Saipan was no small coral atoll. It was about 14 miles long, with varied terrain, towns, cane fields, caves, ridges, cliffs and a large civilian population. It was also strongly held by Japanese forces who understood that the island was a shield for the inner defence perimeter of the Japanese Empire.
The assault formed part of Operation Forager, the American campaign to seize the Mariana Islands. Saipan, Tinian and Guam were of immense strategic value because they could provide airfields within range of Japan for the new B-29 Superfortress bombers. Until then, bombing Japan from China had been difficult, inefficient and logistically fragile. The Marianas offered something far more direct: permanent American air bases in the Central Pacific from which the Japanese home islands could be attacked regularly. For that reason, Saipan was not merely a battlefield. It was a strategic gateway.
Task Force 52 was the Northern Attack Force under Vice Admiral Richmond Kelly Turner. Its purpose was to deliver the assault troops to Saipan, support the landings, protect the transports, and coordinate the complicated movement of ships, landing craft, naval gunfire and supplies. The main landing force was the V Amphibious Corps under Lieutenant General Holland M. “Howlin’ Mad” Smith, with the 2nd Marine Division and 4th Marine Division making the initial assault. The Army’s 27th Infantry Division was held as a reserve and would later be committed to the battle.
The scale of the operation was enormous. The American force included transports, landing ships, landing craft, battleships, cruisers, destroyers, minesweepers, fire-support vessels and logistics ships. The assault required careful timing between naval bombardment, air strikes, underwater demolition work, movement across reefs and beaches, and the landing of thousands of Marines under fire. Saipan tested the entire American amphibious system: planning, command, communications, naval gunfire, air support, beach control, evacuation of casualties, and the constant flow of ammunition, food, water and reinforcements.
Before the landing, Saipan was subjected to heavy naval and air bombardment. American carrier aircraft struck Japanese airfields, gun positions and installations. Battleships, cruisers and destroyers shelled the island. Yet, as was so often the case in the Pacific war, bombardment could not destroy every defensive position. Japanese troops had used caves, ravines, reverse slopes and concealed strongpoints to survive the shelling. Many defenders waited for the landing craft to come within range before opening fire.
The landing beaches lay on the western side of Saipan, around Charan Kanoa. The Marines came ashore on beaches designated Red, Green, Blue and Yellow. The 2nd Marine Division landed on the left, while the 4th Marine Division landed on the right. The first assault waves went in during the morning of 15 June after a final bombardment. Amphibian tractors carried Marines across the reef toward the beaches, while landing craft brought in follow-up waves and heavier equipment where conditions allowed.
The approach was dangerous. Japanese artillery, mortars, anti-boat guns and machine guns began striking the landing area. Some landing craft were hit before reaching shore. Others became disorganised by fire, surf, coral and confusion. Smoke, dust, shell bursts and the noise of naval guns made control difficult. Units landed under heavy pressure and, in some cases, not exactly where intended. The beaches quickly became crowded with men, equipment, wrecked vehicles and incoming supplies.
Once ashore, the Marines found that the battle did not end at the waterline. The Japanese had prepared inland positions that overlooked the beaches. Artillery and mortars continued to fall on the landing zones. Tanks and anti-tank guns threatened the beachhead. The Marines had to push inland quickly to prevent the beaches from becoming killing grounds, but movement was difficult. The terrain beyond the beaches included cane fields, ditches, villages, low ridges and concealed defensive positions. Japanese resistance was stubborn and well organised.
By the end of the first day, the Americans had established a beachhead, but it was not deep enough to be secure. The Marines had landed in force, but they had paid heavily for the ground gained. Japanese counterattacks were expected, and the enemy still held much of the high ground and interior of the island. The landing had succeeded in the basic sense: American troops were ashore and could not easily be thrown back into the sea. But the battle for Saipan had only begun.
The Japanese response showed why Saipan was such a severe test. The defenders included elements of the 43rd Division and other army and naval units. Their commander, Lieutenant General Yoshitsugu Saito, understood the importance of the island. Japanese doctrine emphasised aggressive resistance, local counterattacks and the use of terrain to bleed the attacker. Saipan’s caves, cliffs and broken ground gave the defenders natural protection. Unlike the tiny atolls of Tarawa or Kwajalein, Saipan offered depth. The Japanese could fall back, regroup and continue fighting from successive positions.
During the night after the landing, Japanese forces launched counterattacks against the American beachhead. Tanks were used in an attempt to break through the Marines’ lines. The fighting was fierce, confused and close. Naval gunfire, Marine anti-tank weapons, artillery and small-arms fire helped defeat these attacks. The failure to destroy the beachhead during the first critical night was a major blow to Japanese hopes. Once the Americans had secured their foothold and continued to bring in men, artillery, tanks and supplies, the defenders faced an increasingly powerful enemy.
The landing on Saipan differed from earlier Central Pacific assaults in several important ways. Tarawa in November 1943 had been a shocking lesson in the cost of attacking a fortified coral atoll. Kwajalein and Eniwetok in early 1944 had shown improvement in planning, fire support and logistics. But Saipan was larger and more complex. It required a longer campaign ashore, more extensive supply arrangements, and coordination between Marine and Army formations over varied terrain. The battle was not only an amphibious assault; it became a sustained land campaign.
The size of Saipan also meant that civilians became a tragic part of the battle. Thousands of Chamorro and Japanese civilians were on the island. Many were caught between the advancing Americans and the defending Japanese forces. Japanese propaganda had warned civilians that capture by the Americans would bring torture or death. As the battle moved northward in July, many civilians fled with the retreating Japanese. The final days of the battle witnessed mass civilian suicides at places such as Marpi Point and Banzai Cliff, one of the most haunting tragedies of the Pacific war.
For the United States, Saipan was a victory of amphibious organisation as much as battlefield courage. Task Force 52’s role was central because amphibious warfare depended on the precise union of sea, air and land power. Ships had to place troops on the correct beaches at the right time. Naval guns had to suppress enemy positions without hitting friendly troops. Landing craft had to maintain a flow of reinforcements and supplies. Beach parties had to organise chaos under fire. Medical evacuation had to function from exposed shorelines. Commanders had to adapt as plans met reality.
The seizure of Saipan also triggered a major naval reaction. The Japanese Combined Fleet attempted to challenge the American invasion by attacking the U.S. Fifth Fleet. This led to the Battle of the Philippine Sea on 19–20 June 1944, often called the “Great Marianas Turkey Shoot” because of the devastating losses inflicted on Japanese naval aviation. Although this battle was fought at sea, it was directly connected to the landing on Saipan. Japan could not allow the Marianas to fall without attempting a decisive response. The failure of that response left the defenders on Saipan increasingly isolated.
The land battle continued for nearly a month. American forces pushed across the island, captured Aslito airfield, drove through the central highlands, and gradually compressed Japanese resistance toward the northern end. The fighting was brutal. Caves had to be cleared one by one. Flame-throwers, demolition charges, tanks, artillery and close infantry assaults became essential. Japanese soldiers often fought to the death rather than surrender. On 7 July 1944, the remaining Japanese forces launched a massive final banzai attack, one of the largest of the Pacific war. It caused severe American casualties but could not change the outcome. Saipan was declared secured on 9 July 1944.
The consequences were immense. The fall of Saipan brought the Japanese home islands within range of sustained strategic bombing from the Marianas. It also caused a political crisis in Tokyo. Prime Minister Hideki Tojo and his cabinet fell soon after the loss. The island became a major American base, and nearby Tinian would later serve as the launching point for the atomic bomb missions against Hiroshima and Nagasaki in August 1945.
The landing of Task Force 52 on Saipan therefore deserves to be seen as a turning point in the Pacific war. It demonstrated that the United States had developed the amphibious strength, logistical depth and operational confidence to assault major defended islands far from existing bases. It showed that American sea power could deliver and sustain large ground forces across vast distances. It also proved that Japan’s inner defensive perimeter could be broken.
Saipan was won at great cost, and its human tragedy was profound. For the Marines, soldiers, sailors and airmen involved, it was a hard and bloody campaign fought across beaches, cane fields, ridges and caves. For Japan, it was a strategic disaster. For the United States, it was the opening of the road to the final phase of the war. The landing on 15 June 1944 was not just an amphibious operation. It was the moment when American amphibious might reached the doorstep of Japan’s inner empire and proved that even large, fortified island bastions could be taken.
