For seventy two days before the American landings planes had been bombing the heavily fortified base on Iwo Jima. Marines of the 4th and 5th Divisions made the landing under cover from their own ships. Casualties were heavy, two thousand Marines gave their lives in storming the beaches and advancing towards the first of the airstrip.
The
Battle of Iwo Jima (19 February – 26 March 1945) was a major battle in which the United States Marine Corps and Navy landed on and eventually captured the island of
Iwo Jima from the
Imperial Japanese Army (IJA) during
World War II. Lying roughly halfway between American Army Airforce bases in the Mariana Islands and the Japanese islands, the military base on Iwo Jima gave the Japanese an ability to send early air raid warnings to the Japanese mainland and launch fighters from its airfields to intercept raids.
After the
American capture of the Marshall Islands, and the devastating
air attacks against the Japanese fortress island of
Truk Atoll in the
Carolines in January 1944, the Japanese military leaders reevaluated their situation. All indications pointed to an American drive toward the
Mariana Islands and the Carolines. To counter such an offensive, the IJA and the
Imperial Japanese Navy (IJN) established an
inner line of defenses extending generally northward from the Carolines to the Marianas, and thence to Japan via the Volcano Islands, and westward from the Marianas via the Carolines and the Palau Islands to the Philippines.
In March 1944, the
Japanese 31st Army, commanded by General
Hideyoshi Obata, was activated to garrison this inner line. (Note that a Japanese army was about the size of an American,
British Army, or
Canadian Army corps. The Japanese Army had many
armies, but the
U.S. Army only had
ten at its peak, with the 4th Army, the 6th Army, the 8th Army, and the 10th Army being in the
Pacific Theater. Also, the 10th Army only fought on
Okinawa in the spring of 1945.)
The American invasion, designated
Operation Detachment, had the purpose of
capturing the island with its two airfields: South Field and Central Field. The strategic objectives were twofold: the first was to provide an emergency landing strip for battle-damaged B-29s unable to make it back to US air bases in the Marianas
Tinian,
Saipan,
Guam. The second was to provide air fields for fighter escorts, long-range P-51s, to provide fighter coverage to the bombers. The five-week battle saw some of the fiercest and bloodiest fighting of the
Pacific War.
The IJA positions on the island were heavily
fortified, with a dense network of
bunkers, hidden
artillery positions, and 18 km (11 mi) of tunnels. The American ground forces were supported by extensive
naval artillery, and had complete
air supremacy provided by U.S. Navy and Marine Corps aviators throughout the battle.
Japanese combat deaths numbered three times the number of American deaths although,
uniquely among Pacific War Marine battles, American total casualties (dead and wounded) exceeded those of the Japanese. Of the 21,000 Japanese soldiers on Iwo Jima at the beginning of the battle, only 216 were taken prisoner, some of whom were captured because they had been knocked unconscious or otherwise disabled. The majority of the remainder were killed in action, although it has been estimated that as many as 3,000 continued to resist within the various cave systems for many days afterwards, eventually succumbing to their injuries or surrendering weeks later.
The last of these
holdouts on the island, two of Lieutenant Toshihiko Ohno's men, Yamakage Kufuku (山蔭光福, Yamakage Koufuku) and Matsudo Linsoki (松戸利喜夫, Matsudo Rikio), lasted four years without being caught and finally surrendered on 6 January 1949.
Though ultimately victorious, the American victory at Iwo Jima had come at a terrible price. According to the official Navy Department Library website, "The 36-day (Iwo Jima) assault resulted in more than
26,000 American casualties, including 6,800 dead." By comparison, the much larger scale 82-day
Battle of Okinawa lasting from early April until mid-June 1945 (involving five U.S. Army and two Marine Corps divisions) resulted in over 62,000 U.S. casualties, of whom over 12,000 were killed or missing. Iwo Jima was also the
only U.S. Marine battle where the American casualties exceeded the Japanese, although Japanese combat deaths numbered three times as many as American deaths.
Two US Marines were captured during the battle,
neither of whom survived their captivity. The
USS Bismarck Sea was also lost, the last U.S. aircraft carrier sunk in WW2. Because all civilians had been evacuated, there were
no civilian casualties at Iwo Jima, unlike at Saipan and Okinawa.
In
hindsight, given the number of casualties, the
necessity and long-term significance of the island's capture to the outcome of the war became a
contentious issue and
remains disputed. The Marines, who suffered the actual casualties, were not consulted in the planning of the operation. As early as April 1945, retired Chief of Naval Operations
William V. Pratt stated in
Newsweek magazine that considering the "
expenditure of manpower to acquire a small, God-forsaken island, useless to the Army as a staging base and useless to the Navy as a fleet base ... [one] wonders if the same sort of airbase could not have been reached by acquiring other strategic localities at lower cost."
The lessons learned on Iwo Jima served as guidelines for the following
Battle of Okinawa and the
planned invasion of the Japanese homeland. For example, "because of the casualties taken at Iwo Jima on the first day, it was decided to make the preparatory bombardment the heaviest yet delivered on to a Pacific island". Also, in the
planning for a potential attack on the Japanese home islands, it was taken into account that around
a third of the troops committed to Iwo Jima and again at Okinawa had been killed or wounded.
The
justification for Iwo Jima's strategic importance to the United States' war effort has been that it provided a landing and refueling site for long-range fighter escorts. These escorts
proved both impractical and unnecessary, and only ten such missions were ever flown from Iwo Jima. By the time Iwo Jima had been captured, the bombing campaign against Japan had switched from daylight precision bombing to nighttime incendiary attacks, so
fighter escorts were of limited utility.
