The shelling of Iwo Jima

At the end of January 1945 the US Navy once again bombarded Iwo Jima – a small volcanic island in the Volcano Islands (Kazan Rettō), lying roughly halfway between the Marianas and Tokyo. According to the American official histories, Rear Admiral Allan E. Smith’s force of cruisers and destroyers – the heavy cruisers USS Chester, Pensacola and Salt Lake City with their escort – opened fire on the island on 24 January, in an attack coordinated with a raid by Army Air Forces bombers. News of the bombardment reached the public a day later, in fleet headquarters communiqués, which is why some war chronicles record the event under 25 January.

It was not the first such attack but one more in a series. Since the strike of 8 December 1944, Consolidated B-24 Liberator bombers from the Marianas had attacked the island day after day, and Smith’s cruisers had already shelled it on 8, 24 and 27 December and on 5 January, taking in the neighbouring islands of Chichi-jima and Haha-jima along the way. The January bombardment was thus part of a long, methodical campaign intended to prepare the ground for a landing. It also signalled where the Americans’ next great blow in the Central Pacific would fall.

Why Iwo Jima

The island’s importance stemmed from the American air offensive against Japan. From the autumn of 1944 the Boeing B-29 Superfortress bombers of XXI Bomber Command had been flying from Saipan, Tinian and Guam – on 24 November they attacked Tokyo for the first time. The flight to Japan was about 2,400 kilometres each way and passed over Iwo Jima. Japanese fighters from its two airfields intercepted the bombers, its radar station warned the home islands of incoming raids, and from November 1944 to January 1945 aircraft taking off from or staging through Iwo Jima attacked the airfields in the Marianas and destroyed B-29s parked there.

Taking the island was meant to reverse this situation: to remove the Japanese early-warning post, to give American escort fighters a base within range of Japan, and to give damaged bombers an emergency airfield halfway home. January showed how badly this was needed. During the B-29 raids on Japan in January 1945, high-altitude precision bombing produced disappointing results, while losses of aircraft and crews were heavy. On 20 January Major General Curtis LeMay took over XXI Bomber Command and soon radically changed the tactics of the raids.

Operation Detachment

The decision to take Iwo Jima was made by the US Joint Chiefs of Staff on 3 October 1944, when they ruled that instead of Formosa the objectives would be Luzon, the Volcano and Bonin Islands, and Okinawa. Admiral Chester Nimitz was given the task of capturing Iwo Jima, originally with a target date of 20 January 1945. The operation was named Detachment. The prolonged fighting in the Philippines – on Leyte, and then the landing in Lingayen Gulf on 9 January – tied up the fire-support ships, transports and escort carriers that were also to take part in the Iwo Jima landing, however. The date was put back first to 3 February and finally to 19 February 1945.

Overall command lay with Admiral Raymond Spruance, commander of the Fifth Fleet. The amphibious forces were led by Vice Admiral Richmond Kelly Turner, the expeditionary troops by Lieutenant General Holland Smith, and the landing force itself by Major General Harry Schmidt, commander of V Amphibious Corps. Three Marine divisions were assigned to the battle: the 4th and 5th, which were to land first, and the 3rd in reserve – some 70,000 men in all. In January 1945 the divisions were completing their training and landing exercises in Hawaii, while the staffs refined their plans on the basis of aerial photographs of the island.

An island that went underground

The bombardment of 24 January, like the earlier ones, struck an island ever better prepared for defence. The garrison was commanded by Lieutenant General Tadamichi Kuribayashi, who since June 1944 had been rebuilding the defences according to his own concept. In the summer of 1944 the island’s civilian inhabitants – about a thousand people – were evacuated, and Iwo Jima became purely a fortress. At the end of 1944 it held some 21,000 Army and Navy troops; the naval units were commanded by Rear Admiral Toshinosuke Ichimaru.

Kuribayashi had no intention of defending the beaches or launching mass night counter-attacks, which on other islands had quickly bled garrisons white. His soldiers dug tunnels and underground positions in the soft volcanic rock, linking bunkers, shelters and stores, and artillery positions were sited so as to fire on the beaches only once the infantry had landed on them. The area of Mount Suribachi in the south of the island was prepared for independent defence. According to accounts cited in the historiography, Kuribayashi circulated pledges among his soldiers by which each of them was to fight to the end and kill ten of the enemy before dying.

American bombs and shells made life hard for the Japanese: they destroyed buildings and aircraft on the airfields, cut off supplies and forced the men to work at night. Against deeply hidden defences, however, they achieved little. The official history of the US Marine Corps notes that aerial photographs from early 1945 showed the number of fortifications on the island growing rather than shrinking despite the raids and bombardments.

The dispute over the length of the bombardment

It was these very photographs that lay behind a dispute which divided the operation’s planners in the winter of 1944–1945. According to American studies, General Schmidt demanded ten days of heavy naval bombardment immediately before the landing. Rear Admiral William Blandy, who was to command the fire-support force, replied that with a bombardment of that length the ships would not have time to replenish their ammunition before the landing, and proposed three days. The Marines repeated their requests – for nine days, and then for four – but to no avail. Spruance held to three days, citing among other things the simultaneous strikes planned by Vice Admiral Marc Mitscher’s carriers against the Tokyo area, which were meant to stop Japanese air power from intervening at Iwo Jima but took some ships away from the fleet.

The decision left deep resentment in the Marine Corps. After the war Holland Smith repeatedly accused the Navy of costing his men their lives by providing too little fire support. Historians judge the dispute differently: some believe that a longer bombardment would have saved many lives, while others point out that against defences hidden in rock even ten days of fire would not have been decisive. The January bombardments by Smith’s cruisers, short and several weeks apart, served as arguments for both sides in this dispute – they showed both the fleet’s determination and the limited effectiveness of such operations.

Place in the war

The bombardments and raids continued right up to the landing. At the turn of January and February the Liberators from the Marianas were flying thirty-odd sorties a day over the island, and on 16 February Blandy’s ships began the three-day preparatory bombardment, hampered by bad weather. On 19 February 1945 the 4th and 5th Marine Divisions landed on the island’s south-eastern coast and the Battle of Iwo Jima began. Kuribayashi’s underground defences, largely untouched by weeks of bombing, held out until 26 March. Some 6,800 Americans were killed, and total American casualties – more than 26,000 killed and wounded – exceeded the Japanese; of the roughly 21,000 defenders only about two hundred were taken prisoner.

The island then served its purpose: according to the official history of the US Army Air Forces, 2,251 B-29 landings were recorded there by the end of the war, and fighters escorting the raids over Japan flew from its airfields. The experience of Iwo Jima – above all, how little bombs and shells could achieve against defences hidden in rock – weighed on the preparations for the Battle of Okinawa, which was preceded by a much longer bombardment, and on the casualty estimates in the plans for the invasion of Japan. The bombardment of 24–25 January 1945 was one of many links in this story: small in scale, but characteristic of a whole campaign in which the Americans pounded the island for ten weeks while its defenders went ever deeper underground.