The Battle of Iwo Jima, 19 February – 26 March 1945
-Jason
The Battle of Iwo Jima, fought between 19 February and 26 March 1945, was one of the last major battles of the Pacific Theater during World War II. The island gained strategic importance as the Allies captured territory closer and closer to Japan. American planners expected a difficult fight for Iwo Jima but were surprised by the number, and tenacity, of Japanese defenses.
Iwo Jima is in the Bonin Islands, a chain of volcanic islands, roughly 750 miles south of Tokyo. The highest point on Iwo Jima is Mount Suribachi, which became famous due to Joe Rosenthal’s picture of the American flag being raised, and it dominates the south tip of the island. At around 8 square miles, this tiny island was one of the most heavily defended places in the world. Iwo Jima was the sight of terrifying combat on the land, air, and sea that would shape future Allied operations against Japan.
The Americans had advanced across the Central Pacific between 1942 and 1944 crushing the Imperial Japanese Army and Navy they encountered. The capture of the Marshall Islands between June and August 1944 had been a key strategic objective for the Allies. The Americans had been developing an extremely long-range heavy bomber to conducted raids on the Japanese homelands. Airbases for the B-29 Superfortress had been constructed in China, but the task of resupplying and protecting those facilities proved impossible. Guam, Saipan, and Tinian were the three most important locations in Marshall Islands. Those islands, once captured, would be converted into massive airfields to service the B-29s shipped to the Pacific.
The Marshall Island based B-29 raids on Japanese cities took several months to put into action. Aircrews needed to contend with the jet stream that roared over Japan and had to adapt their tactics. The B-29 was the first fully pressurized heavy bomber, designed to operate at high altitudes. The long range of the B-29 allowed the crew to bring plane to targets beyond the limits of contemporary aircraft. Despite having an extremely advanced bombing system onboard, the jet stream over Japan would blow the munitions off target at high altitude. American aircrews shifted tactics to find the correct altitude, speed, and payload that was most effective in raiding Japanese targets. American casualties began to mount as the B-29s switched tactics to bomb at lower heights and this needed to be addressed.
The B-29s had such long range that they were not accompanied by escorting fighter aircraft. The Americans had to fend off Japanese interceptors with only their onboard defensive armament. Land based anti-aircraft weapons also damaged B-29s once they descended beneath the jet stream. Any bombers that were damaged over Tokyo had to attempt the long and dangerous flight back to the Marshall Islands: a return trip of 1459 miles. Between Japan and the Marshalls were several small chains of volcanic islands held and armed by the Japanese including the gauntlet of airbases on Iwo Jima. American losses mounted in terms of not just aircraft, but also trained aircrew; a solution was presented: the capture of Iwo Jima and the surrounding Bonin Islands. The capture of the south and central airfields were the key objectives of Operation Detachment. Once secured, those airfields would be used for two reasons: they would serve as a base for American fighter aircraft that could support the heavy bombers, and they would be an emergency landing field for damaged B-29s.
The United States Navy and Marine Corps formed the major components of the Allied invasion force. Beginning in June 1944, the US Navy and Army Air Corps conducted one of the most intense and longest operations of the Pacific War. American aircraft carriers destroyed most of the Japanese aircraft on the ground while battleships and cruisers bombarded the island. By the time of the invasion, 450 Allied warships did the important work of destroying the reinforcement and resupply shipments sent from Japan to Iwo Jima paving the way for 60,000 Marines to invade.
Despite this Allied interdiction, the Japanese commander Lieutenant General Tadamichi Kuribayashi constructed a labyrinth of defensive features across the island. Kuribayashi understood that he could not win the battle, but he hoped that his 21,000 soldiers would inflict such heavy casualties on the Allies to convince them to not invade mainland Japan. To this end, the Japanese built enormous fortifications both along slopes, and inside, of Mount Suribachi. Kuribayashi also changed the usual Japanese tactics against Allied invasion: he ordered his men to endure the pre-landing bombardments and allow American troops to get ashore instead of defending the beaches. He believed that if American and Japanese formations became entangled, the superiority of US firepower could not effectively be used.
Operation Detachment began on 19 February 1945 with heavy naval and air bombardments raking the island for three days prior to the landing. Years of bitter fighting in the Central Pacific had proven to the Americans that no matter how intense the bombardment, Japanese defenders would still survive. US Marine Major General Harry Schmidt asked Rear Admiral William Blandy for a ten-day pre-landing bombardment but was refused because the US Navy commander feared his ships would not have time to rearm before the actual landing took place. The three-day bombardment, which was not entirely fulfilled, was a compromise and forced the US Marines to endure hard fighting.
As the American amphibious landing craft neared the beaches, the Marines noticed the lack of heavy Japanese resistance. US forces landed on the soft black volcanic sands of Iwo Jima and were surprised at how it nearly swallowed larger pieces of equipment and vehicles. The planners at Pearl Harbor had labeled the beaches as “excellent” without realizing that 15-foot-tall slopes made exiting the shoreline difficult. The Japanese unleashed their hidden machine guns and artillery pieces at 10:00 am. The volcanic ash was so loose that foxholes could not be dug by the Marines, and they suffered under the Japanese fire.
Japanese defenses located within Mount Suribachi added firepower to their bunkers near the beaches. Heavy, swivel operated steel doors opened allowing large artillery pieces to fire and then retreat before counterbattery fire could destroy them. The bunkers across the island were connected by an elaborate tunnel system that allowed Japanese defenders to reoccupy overrun positions. Areas the US Marines thought that they had secured suddenly opened fire on them again. Casualties mounted as the opposing forces became intertwined.
US Marines pushed for their first day objectives despite the fierce Japanese resistance. Mount Suribachi was cut off from the rest of the island but still needed to be stormed. By nightfall, 30,000 Marines had landed; they would eventually be joined by another 40,000 during the subsequent campaign. Once night fell, the Marines endured suicidal banzai charges that were designed to overwhelm small American detachments. Kuribayashi had ordered his soldiers not to conduct large human wave attacks: he wanted to inflict maximum damage on the Americans with minimum losses to his forces. Even with the airfields soon under their control, the Americans had a difficult time defeating the Japanese.
The Japanese also had another defensive strategy in mind to damage American forces: kamikaze air attacks. Experienced Japanese pilots had been decimated between 1941 and 1945 but aircraft had still been produced. During the Liberation of Philippines, the Americans had been struck by the first waves of suicidal aircraft Japanese attacks. Inexperienced Japanese pilots were ordered to crash their planes into American warships. If one plane could disable, or sink, an American warship, the Japanese felt that the Allies would sue for peace without invading the Home Islands. While this tactic was ultimately unsuccessful, the number of casualties inflicted upon US forces brought to light how difficult the invasion of the Japanese homeland would be.
On 23 February 1945 one of the most iconic photos of World War II was captured when the US Marines raised the American flag on Mount Suribachi. Six Marines set the Stars and Stripes for a second time that day while Joe Rosenthal snapped the picture. Rosenthal’s picture won the Pulitzer Prize for Photography that same year. Of the six Marines who raised the flag, three were killed within the subsequent days of the campaign on Iwo Jima and the others were pulled from the front lines. With fall of the southern part of Iwo Jima, Kuribayashi and his remaining soldiers launched one final suicidal attack on American forces on 24 March. After their commander was killed, Japanese forces continued to launch small uncoordinated assaults for the remainder of the war.
Bitter fighting finally resulted in the island being declared secure on 26 March 1945. The two formerly Japanese airfields were expanded by the Americans to service both fighter escorts and damaged B-29 bombers. The cost of securing the island was 26,000 American casualties, including 6,800 dead, over 36 days of intense combat. Several US Navy warships were severely damaged and retired from the theater for repairs. The Japanese garrison had been decimated, losing roughly three times the number of US casualties. Despite the heavy losses suffered, several Japanese soldiers held out on Iwo Jima before surrendering themselves in 1949. The Battle of Iwo Jima has been immortalized and remember by both the Americans and Japanese as anniversary celebrations were conducted by veterans of both sides. Pilgrimages to Mount Suribachi by survivors or family members of US Marines take place often as well as the Japanese government attempting to recover and identify the remains of their servicemembers.