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Iwo Jima


Digital relief map of Iwo Jima

Photograph of Iwo Jima

National Archives #80-G-310939


Iwo Jima (141.290E 24.754N) is the largest of the Volcano Islands, located about 650 miles (1050 km) south of Tokyo. It is shaped like a pork chop, some 4.7 miles (7.6 km) long, with Mount Suribachi (550 feet or 168 meters) at the southern tip and the Motoyama Plateau to the north. The total land area is about eight square miles (21 km2). Geologically, the island is a resurgent dome in a submerged caldera, which is capable of erupting again.

The area between Motoyama and Suribachi rises to about 60' (30 meter) elevation and is bare flat ground devoid of cover, except for some slight cover from low dikes separating subsistence gardens to the west. Motoyama averages about 200' to 300' (60 to 100 meters) in elevation with a number of higher ridges and ravines.

The beaches are volcanic cinder with no really decent landings and the island has no fresh water supply except rainfall. The cinder was incapable of supporting wheeled vehicular traffic and was difficult even for tracked vehicles to get any purchase on. Men on foot sank into the cinder to their ankles and it was almost impossible to dig foxholes, because the cinder rapidly flowed back into any hand excavation. The cinder was also infested with large numbers of sand fleas. The ocean bottom drops rapidly offshore, at something close to a 45 degree angle, and there are no offshore rocks or reefs. The steep bottom and lack of any protection from surf increased the difficulty of landing operations. On the other hand, it was also difficult for the Japanese to emplace defensive obstacles and mines.

The climate is subtropical, with temperatures from 50-78F (10-25C) from December to April and 60-85F (15-30C) from May to November. Rainfall averages 60" (150 cm) per year, with February the driest month and May the wettest, but there was frequent rain during the American invasion in spite of it taking place in the driest season of the year.

Sugar and pineapple were cultivated here prior to the war, and sulfur was extracted from volcanic deposits. However, the civilian population of 1100 persons was evacuated before the American invasion

Iwo Jima was not considered militarily important by the Japanese until after the fall of the Marshalls, and the island was not heavily reinforced until March 1944. Prior to that time, the single small airfield, built in 1940, could accommodate perhaps 20 aircraft, and the garrison, which arrived in 1941, numbered about 1500 men. The Japanese expanded the original airfield, constructed a second airfield, and were working on a third at the time of the American invasion. Airfield #1 (Chidori Airfield), to the south, had 5015' (1530 meter) and 3965' (1210 meter) runways. Airfield #2 (Motoyama Airfield) in the center of the island had 5225' (1590 meter) and 4425' (1350 meter) runways, while Airfield #3 in the north had a single uncompleted 3800' (1160 meter) runway. North of Motoyama are two features named Hill PETER and Hill 199-0 that dominated the entire area. 

Carrier Raids

The island was raided on 15 and 16 June 1944 by Task Group 58.1 (Clark), during the Marianas campaign, in order to interdict Japanese aircraft reinforcements. Famed Japanese ace Sakai Saburo was present and described one raid in his autobiography. The American raid was detected sixty miles out, allowing eighty Japanese fighters to scramble against a fighter sweep of just fifty-one Hellcats. The Americans nevertheless inflicted thirty kills against a loss of six Hellcats, a reflection of the poor quality of the Japanese trainee pilots being committed to combat at this point in the war. Sakai himself, leading a group of inexperienced pilots in spite of being half blind from injuries suffered at Guadalcanal, managed to survive but claimed no kills.

Another raid was carried out on 24 June 1944 by Clark on his own initiative. Clark had been ordered to retire to Eniwetok for refueling, but correctly guessed that Japanese aircraft intended for the Marianas were present at Iwo Jima and, with Mitscher's approval, he struck Iwo Jima along the way. There were 122 aircraft at Iwo and Chichi Jima, and a Japanese patrol plane detected Clark's force. As a result, the American fighter sweep of 51 Hellcats was met by everything that 27 Air Flotilla (Matsunaga) could put in the air. The Americans shot down 24 Japanese fighters and 5 Judys at the cost of 6 Hellcats. The surviving Americans returned to their carriers just in time to annihilate a Japanese raid by about 20 torpedo bombers. A second Japanese raid failed to find the American ships and lost 7 Jills and 10 Zekes to the American combat air patrol.

Clark struck Iwo again on 4 July 1944, and the Japanese responded by recalling Hachiman Detachment, Usa Air Group to Japan.

Battle of Iwo Jima

The American invasion of the Marianas in June 1944 brought Superfortresses within reach of Japan itself. The direct route to Tokyo passed very close to Iwo Jima, whose radar provided early warning and whose fighters posed a threat to the giant bombers. Furthermore, the Japanese staged a series of raids through Iwo Jima that succeeding in damaging six and destroying eleven Superfortresses on Tinian. Radar picket destroyers stationed 100 miles (160 km) northwest of Saipan provided early warning but failed to detect every raid.

The capture of Iwo Jima would put an end to these raids and provide a base for fighters capable of escorting the Superfortresses to Japan. As a result, on 3 October 1945, the Joint Chiefs of Staff approved a plan for the final approach to Japan that included an invasion of Iwo Jima. B-24 Liberators from Saipan had already begun raiding the island on 10 August 1944, and additional strikes were made against shipping at Chichi Jima. On 8 December 1944, massed raids by 28 P-38s, 62 B-29s, and 102 B24s accompanied by a heavy bombardment by Cruiser Division 5 (Smith) were hindered by foul weather and failed to put the airfields completely out of action. Additional bombardments took place on 24 December, 27 December, 5 January, and 25 January. Aerial bombardment became almost continuous from 31 January onwards. In some cases bombers attacked singly at regular intervals so that the island was under bombardment all night long. By the time the landings took place, about 6800 tons of bombs had been dropped on the island, and the naval bombardments had fired 203 16" (406mm), 6472 8" (203mm), and 15,251 5" (127mm) shells at the island.

Marine commanders Smith and Schmidt wanted ten days of preliminary bombardment prior to the landings, but were overruled by Spruance and Turner, who limited the bombardment to three days. Spruance wished to mount a carrier raid on Japan simultaneously with the landings, and he feared that ten days of bombardment would give away surprise and leave his forces vulnerable to kamikazes. Spruance and Turner were also worried about logistics, believing that ten days' bombardment would deplete the ammunition supply faster than the fleet train could bring up more ammunition. Spruance was privately unimpressed with the effectiveness of the aerial bombardment, and he believed that the defenses could be knocked out only once troops were ashore to pinpoint enemy strong points and direct accurate naval fire against them. A further difficulty was that MacArthur had retained control of several battleships for his operations in the Philippines, and the coming typhoon season ruled out postponing the Iwo Jima operation until the battleships were released by MacArthur. Nimitz assigned substitute battleships to the Iwo Jima operation in their place, but these were among the oldest battleships in the U.S. Navy, armed with 12" (305mm) to 14" (356mm) guns rather than the 16" (406mm) guns of the newer battleships.

The Raid on Japan. Spruance's raid on Japan, the first since the Doolittle raid of 1942, sortied from Ulithi on 10 February 1945. The carrier force under Mitscher included 11 fleet carriers and 5 light carriers escorted by 8 battleships, the newly arrived large cruiser Alaska, and 14 other cruisers and 77 destroyers. Because of the kamikaze threat, the air groups of the fleet carriers now consisted of a minimum of 73 fighters with just 30 light bombers. Elaborate measures to ensure surprise included radio deception and scouting by submarines and aircraft to eliminate any Japanese picket boats. The final run into the launch point, 125 miles 200 km) southeast of Tokyo, took place on the night of 15 February and the first strikes were launched at down on 16 February. Poor weather helped ensure surprise was achieved, but also hindered air operations. The American strikes encountered about 100 Japanese fighters over Chiba and shot down 40. The Japanese pilots were reportedly reluctant to engage. Successive fighter sweeps caught additional Japanese aircraft on the ground, and the Americans later claimed a total of 341 aircraft destroyed in the air and 190 on the ground at the cost of 88 American aircraft. The Japanese admitted to 78 aircraft shot down but gave no figures for those lost to strafing and bombing. The Ota aircraft plant was severely damaged, but the weather hindered accurate bombing of Koizumi. Additional strikes were made on 17 February against Musashino, Tama and Tachikawa aircraft plants before Mitscher called off further strikes because of the deteriorating weather.

Photograph of landing craft coming ashore on Iwo Jima

U.S. Marine Corps. Via ibiblio.org

Landings on Iwo. On 16 February 1945, Allied warships under Blandy, including the newly arrived British Cruiser Squadron 4 (Brind), began systematically bombarding the island. The bombardment force under Rodgers was supported by escort carriers under Durgin and a minesweeper force under Sharp. The escort carriers included Wake Island, which carried VOC-1, a gunfire spotting group flying modified fighter aircraft. Poor weather hampered the spotters on 16 February and Admiral Rodgers reported at the end of the day that "Little damage was apparent" (Morison 1959).

The weather was better on 17 February and the bombardment ships closed with the shore to fire at close range. Pensacola received six hits from coastal guns that inflicted numerous casualties but did not put the cruiser out of action. When several LCPRs carrying underwater demolition teams and supported by seven LCI gunboats approached the shore, the Japanese concluded that the main landings had begun and opened fire from numerous positions that had previously remained concealed. The LCIs took the brunt of the fire, with several retiring to be replaced by reserve LCIs. One LCI was sunk and another eleven damaged. However, the UDTs completed their mission, confirming that there were no serious beach obstacles and mapping the beach gradient. The premature exposure of so many Japanese gun positions was one of the few serious Japanese errors in the battle: The Japanese positions were carefully charted and brought under bombardment the next day, with particularly effective fire coming from battleships Tennessee and Idaho, and many were neutralized.

That evening, a Japanese air raid succeeded in putting two small bombs into destroyer-minesweeper Gamble and a single bomb into destroyer-transport Blessman, damaging both severely.

Task Force 53 (Hill) began landing V Amphibious Corps at 0900 on 19 February. The weather was excellent, with little cloud cover to hinder spotting aircraft or wind to raise surf on the steep landing beaches. A final bombardment preceded the landings, with each of the six battleships firing 75 rounds and each of the nine heavy cruisers firing 100 rounds. This was followed by bombs, rockets, and napalm from carrier aircraft, the battleships fired another 155 rounds each and the cruisers 150 rounds, plus 500 rounds from each of the nine destroyers in the bombardment force. Fire then shifted inland as the first troops landed, at which point the naval gunfire was directed by shore fire control parties. By the end of the first day, the bombardment force had fired a total of 475 16" (406mm) shells, 1325 14" (356mm) shells, 175 12" (445 mm) shells, 2100 8" (203mm) shells, 3000 6" (152mm) shells, and 36,260 5" (127mm) shells.

Optimists predicted that the island would be secured in four days. At first, that seemed possible, as the LVTs carrying the first five waves of troops emerged from their LSTs and churned ashore under relatively light fire.  The landing beaches stretched from just northeast of Suribachi to the East Boat Basin halfway up the southeast coast of the island, with 5 Marine Division (Rockey) on the left and 4 Marine Division (Cates) on the right. Covering fire for the LVTs was provided by twelve of the new LCS(L) gunboats. However, a set of three natural terraces up to 15' (5m) high, created by a storm in 1943, lay in back of the beaches and blocked further movement inland by the LVTs. Japanese fire began to pick up within minutes of the first troops coming ashore, and within half an hour was heavy and accurate, particularly on 4 Marine Division's landing beaches, which were well observed from Japanese posts on high ground just north of the East Boat Basin.

The Marines quickly discovered that the Japanese defending Iwo Jima were holed up in some of the most elaborate fortifications of the war. The garrison consisted of 109 Division (Kuribayashi) plus 30 tanks and a hodgepodge of Army and Navy support troops organized for ground combat, for a total of 13,586 soldiers and 7,347 sailors. An additional 1500 men were assigned to the garrison but were lost at sea to Allied shipping strikes. The Army troops were equipped with twelve 320mm spigot mortars; 22 150mm trench mortars; four 150mm, four 140mm, and 21 120mm coast defense guns; 30 120mm, six 100mm, five 80mm, and 18 75mm dual-purpose guns, one 150mm, four 120mm, six 100mm, four 90mm, and five 75mm pack howitzers; 17 75mm and 24 70mm field guns; and hundreds of smaller mortars and machine guns. The Navy contingent, led by Ichimaru Toshinosuke, was equipped with a dozen 4.7" (120mm) and 6" (155mm) coast defense guns, 12 heavy antiaircraft guns, and 30 dual 25mm antiaircraft guns.

Kuribayashi had correctly anticipated that the landings could only take place on the beaches north and east of Suribachi, and, believing the beaches and Airfield #1 would be swept by overwhelming Allied firepower, he concentrated the Army defenses on Suribachi and Motoyama Plateau. His main defense line was placed on good defensive terrain between Airfield #1 and Airfield #2. However, the naval officers on the island demanded that an effort be made to stop the attack on the water's edge, and Kuribayashi  allowed the Navy to build and man a series of pillboxes covering the beaches. Naval guns of 4.7" (120mm) and 6" (155mm) were also positioned to enfilade the beaches. Antiaircraft guns were sited in deep pits and could only be silenced by direct hits, and all these strong points were connected by tunnels. The volcanic cinder covering the island could be mixed with cement to form excellent concrete, and some of the Army bunkers on Motoyama Plateau were six stories deep. The cinder also contained sufficient magnetite that it foiled ordinary mine detectors, and the Japanese sowed minefields freely around their fortifications.The density of fortifications was unprecedented: 5 Division combat engineers claimed after the battle that they destroyed 5000 cave entrances and pillboxes.

As the Marine commanders had feared,  the preliminary bombardments destroyed only about half of the bunkers in the landing area (eleven coastal defense guns, 22 5" dual-purpose guns, sixteen blockhouses, and 45 pillboxes), and the remainder had to be destroyed either by direct hits from heavy naval guns, directed by shore fire control parties assigned one to each battalion, or in close-quarter combat using grenades, demolition charges, and flamethrowers. Air strikes using napalm and 500 pound (227 kg) bombs proved ineffective. Many of the Japanese positions were so well concealed that they could not be spotted before they opened up on the advancing Marines at close range. Nor were the Japanese having an easy time of it. Accurate gunfire from cruiser Santa Fe pinned down the Japanese on Mount Suribachi so effectively that a patrol from 5 Division's 27 Regimental Combat Team reached the western shore by 1035, and Mount Suribachi was isolated by 1500. A pair of large blockhouses behind 5 Division's beaches were taken apart by direct fire from the 14" (356mm) guns of battleship Nevada, which then put two 14" shells into a gun position in a cave overlooking the beaches.

4 Division encountered very stiff opposition, particularly from pillboxes in cliffs overlooking an old quarry inland from East Boat Basin. LCS(L)-51 closed the beach and directed tracer fire against the Japanese positions, which was observed by cruiser Vincennes and used to direct her 6" guns. This proved so effective that several other LCS(L)s teamed up with destroyers in the same way.

The first tanks came ashore in 5 Division's sector at 0930 and in 4 Division's sector at 1000, but had considerable difficulty getting off the beach and suffered many casualties from mines and gunfire. However,Marine tank units eventually proved vital in sustaining the advance, both by providing cover for Marine infantry and by directing their firepower against Japanese positions. Flamethrower tanks proved particularly effective.

Photograph of dug in Japanese tank

U.S. Marine Corps. Via ibiblio.org

Most of the tanks of 26 Tank Regiment were buried up to their turrets in the soft volcanic ash, becoming steel pillboxes. This made them more difficult targets but sacrificed their mobility. Since the battle was characterized by positional warfare with little room for maneuver, this doubtless seemed like a reasonable trade off to the Japanese. By 1100 the wind had shifted to the southeast shore, and the rising surf combined with withering fire to create chaos on the beaches. The reserve waves of troops came ashore in LCVPs and LCMs, which had a difficult time securely grounding on the steep beach. The beach was soon littered with wrecked landing craft.

By the end of the day,  approximately 30,000 Americans (six infantry regiments, six artillery battalions, and two tank battalions) had come ashore, of whom some 2420 had already become casualties. These included 566 who were killed in action or who died of their wounds. The beachhead was just 4000 yards (3700 meters) long and 1100 yards (1000 meters) deep at the point of deepest penetration.

Photograph of Mount Suribachi looming over the landing beaches

U.S. Marine Corps. Via ibiblio.org

Seizing Mount Suribachi. The combat on Iwo Jima soon settled into a weary pattern. Every night, as the Marines dug in to repel infiltrators, their regimental and divisional commanders pored over maps to designate targets for heavy bombardment at first light. The battleships and cruisers would fire for perhaps an hour, then stand off to await further special fire missions while the destroyers, one assigned to each battalion, would move in and prepare to fire on targets identified by shore fire control parties or spotting aircraft. The Marines would step off, only to be met by withering fire from previously undetected positions that only now revealed themselves. The Marines would advance perhaps one or two hundred yards by the time night fell, and the cycle repeated itself.

The warships off the beach also suffered. On the evening of 21 February, Saratoga, serving as a night fighter carrier, was hit by five kamikazes and a conventional bomber that destroyed the forward flight deck and set the hangar deck on fire. The fire was under control by 1830 but Saratoga was out of action for three months. Minutes later, Bismarck Sea was hit by a kamikaze that set her gasoline stores afire and forced her crew to abandon ship. Bismarck Sea burned and exploded for three hours before capsizing. Escort carrier Lunga Point and net cargo ship Keokuk were also damaged by kamikazes.

By nightfall on 22 February the Marines had advanced across Airfield #1 and were at the foot of Mount Suribachi. One company claimed to have destroyed over fifty fortified Japanese positions on its front, and the Marines had already suffered 4500 casualties in three days of fighting. However, the Japanese commander became so desperate that he demanded permission from Kuribayashi to stage a banzai charge (via a radio message intercepted and decoded by Allied intelligence.) Early the next morning, a small detachment of 28 Marine Regiment reached the top of the volcano and, in the midst of a firefight, raised a small flag, visible throughout the combat area and from ships offshore. This was greeted by numerous ship's whistles and temporarily boosted the morale of the ground troops (Wheeler 2007):

The first flag goes up at Suribachi

U.S. Navy. Via ibiblio.org

As we lay in holes that were never too deep, someone yelled, 'Mom, look behind you!' I rolled over on my back and saw the most beautiful thing I have ever seen, Old Glory flying from the top of that pile of rock and sand, Suribachi. After we had been pinned down for so long, no one said a word. I got up and, to a man , we walked forward across the airstrip.

A larger flag was raised some time later; photographer Joe Rosenthal snapped a quick photograph that became perhaps the most iconic photograph of the war. However, the seizure of this high ground did not come close to ending the battle. On Suribachi alone there were still an estimated 1000 Japanese remaining out of the original force of 1600, which continued to tie down 28 Regiment for some time. The Japanese were gradually rooted out with the aid of war dogs.

A few Japanese managed to escape from Suribachi and slip through American lines to reach their own positions in the north. Their reception says much about the Japanese armed forces (Wheeler 1970):

Their uniforms torn and bloodstained, they arrived at the headquarters of naval Captain Samaji Inouye, and the lieutenant explained he had come to report that Suribachi had fallen. He was greeted with a tirade of profanity and abuse. "Shame on you to come here! Shame, shame, shame! You are a coward and a deserter!" The captain's aides tried to calm him, but he went out of control. "A deserter must be executed! I shall behead you myself!" He drew his samurai sword, and the lieutenant knelt in silent submission. But as Inouye raised the weapon, his aides wrested it from him.

Additional Carrier Raids. On 25 February the fast carriers of 5 Fleet launched strikes against Tokyo that encountered such foul weather that Mitscher ordered further strikes canceled. Mitscher then shaped course for Nagoya, but heavy seas forced Mitscher to break off for refueling. On 1 March Mitscher was able to launch effective strikes against Okinawa, which also returned a wealth of photoreconnaissance data for the coming landings.

Aerial photograph of the Motoyama Plateau

Aerial view of Motoyama Plateau. Via ibiblio.org

Seizing Motoyama Plateau. The Marines now moved north to clear Motoyama Plateau. They were aided by fire support from LCI(M)s, armed with three 4.2" mortars and automatic weapons. Their shallow draft allowed them to come close to shore, where they could provide quick fire on call and could shoot up gulleys opening to the sea that were difficult for the ground troops to observe. 3 Marine Division (Erskine) came ashore on 24 February and took position in the center of the line, where the objective of 21 Regiment was a ridge north of the Airfield #2 that dominated the area. Although tank support arrived too late to support the first attempt to take the ridge, the second attempt was successful and a Japanese counterattack was thrown back. Total American casualties in the campaign thus far were 7,758 Marines and 32 tanks.

Photograph of the area east of Minami village

Terrain east of Minami village. Via ibiblio.org

On 25 February 4 Marine Division began to advance into an area around Minami village that became known as The Meat Grinder. Located just east of Airfield #2, this area was defended by elements of 2 Mixed Brigade and 26 Tank Regiment. Important features were dubbed The Amphitheater and Turkey Knob, but the main objective was Hill 382. Hill 382 was reached on 26 February but the advance stalled under fire from a large blockhouse atop Turkey Knob. The Marines finally had to retreat from Hill 382 under cover of a smoke screen. Another attempt on 28 February finally seized Hill 382 for good, though mopping up of The Meat Grinder would continue until 10 March. The Japanese, too, were nearing exhaustion; on this day Kuribayashi sent a message to Tokyo reporting that half his men and two-thirds of his officers had already become casualties, and most of his machine guns and 60% of his big guns were destroyed. An attempt by five dug-in Japanese tanks to emerge and storm the American lines ended with the destruction of all five tanks by bazookas, flamethrowers, and air strikes. One battalion advanced a thousand yards this day, the largest advance since the seizure of the second airfield. The Marines were now in Motoyama village and on a ridge overlooking Airfield #3.

Photograph of first B-29 to land on Iwo Jima

First B-29 to land on Iwo Jima. Via ibiblio.org

28 February also marked the arrival of the first Allied aircraft to be based on Iwo Jima. Initially these were Marine spotting aircraft based on the first airfield and PBM flying boats based on the waters around Suribachi. On 4 March, the first B-29, "Dinah Might", made an emergency landing on Airfield #1, to the cheers of hundreds of Marines and Seabees. By 6 March Army fighters of VII Fighter Command  (Moore) and Navy PB4Y Liberators of  were operating out of #1 Airfield.

On 2 March, elements of 3 Marine Division began approaching an area north of The Meatgrinder that became known as Cushman's Pocket. This was defended by the main strength of 26 Tank Regiment and would take two weeks to reduce. However, by the end of 3 March, though Marine casualties had reached 16,000, the Japanese were down to about 3500 men. Another push by the Marines on 6 March made little progress, prompting Erskine to order a surprise night attack just before dawn on 7 March. The attack went in without preparatory bombardment and almost came to disaster when the troops became disoriented in the darkness. However, a costly diversionary attack on Cushman's Pocket allowed the main attack to push forward to its objective, Hill 362C.

Photograph of Marine infantry and tanks advancing

Marine infantry and tanks advance. Via ibiblio.org

By 8 March the remaining Japanese were confined to a narrow strip along the north and northeast coasts of the island. That evening, Senda ignored Kuribayashi's instructions and ordered the survivors of 2 Independent Mixed Brigade to stage a banzai attack. This brought the Japanese into the open where the full American firepower could be brought to bear, and some 800 Japanese were killed, about half of the attacking force, at the cost of less than 300 Marine casualties. Senda himself survived the attack and holed up in the rugged coastal terrain. The next day 3 Marine Division finally broke through to the sea, and the day after that, The Meat Grinder was finally mopped up.

The Marines had one ordeal remaining. On 10 March elements of 5 Marine Division reached a gully that would become known as Death Valley or The Gorge. This gully extended about 700 yards (640 meters) inland from the northwest coast of the island and was 200 to 500 yards (180 to 460 meters) wide. This was Kuribayashi's final stronghold,manned by about 1500 Japanese. The Americans dropped a massive bombardment on the area, but it was up to the Marine riflemen to reduce the defenses here. By March 16, when the 3 and 4 Marine Divisions finished off all remaining organized resistance on their fronts, Kuribayashi had radioed Tokyo that "The battle is approaching its end" (Wheeler 2007). The island was declared "secured" the same day, but fighting continued, as tank dozers and flamethrower tanks systematically reduced the remaining Japanese positions.

The unreduced area of The Gorge still covered 2500 square yards (2100 meters) on 26 March. That morning, a group of about 350 Japanese emerged from the pocket and fell on a camp full of Seabees and 7 Air Force troops. Fortunately for the rear area troops, the Marine 5 Pioneer Battalion was also camped in the area and drove off the Japanese after a bitter three-hour firefight. Some 330 Japanese were killed and 18 captured, and 7 Air Force suffered 44 killed and almost 100 wounded. This ended organized resistance, though isolated individuals and small groups continued to be mopped up almost until the end of the war.

Total casualties for the Americans were 6812 dead or missing, 19,189 wounded, and 2648 combat fatigue casualties, including Navy casualties. The Japanese losses by the of 26 March were calculated at 20,703 dead and 216 captured. Another 1602 were killed and 867 taken prisoner by the time of the final Japanese surrender.

Iwo Jima was the first experiment by the Japanese in shūgettsu ("bleeding strategy"), which acknowledged no hope of repelling the invaders and sought instead to inflict such casualties on the casualty-averse Americans that they would hesitate to invade the home islands.

The refusal by Spruance and Turner to authorize the ten-day bombardment requested by the Marines became a postwar controversy, with Holland Smith being particularly critical in his memoirs. However, the island was bombarded with an impressive 14,650 tons of explosives, and Navy defenders such as Samuel Eliot Morison suggest that the law of diminishing returns meant that further bombardment would have accomplished little.

Japanese order of battle, 19 February 1945

109 Division (Kuribayashi) 13,586 men
  
2 Independent Mixed Brigade (Senda)     


145 Regiment
Probably the best Japanese troops on the island

3 Battalion, 17 Independent Mixed Regiment     


26 Tank Regiment About 30 tanks
Iwo Jima Naval Guard Force (Ichimaru)
7,347 men

204 Naval Construction Battalion

Allied order of battle, 19 February 1942

V Amphibious Corps (Schmidt)       71,300 men including attached units
  
3 Marine Division (Erskine)
Corps reserve. 3 Marine Regiment was controversially never committed to battle.

4 Marine Division (Cates)


5 Marine Division (Rockey)

Following its conquest, the Americans converted Iwo Jima into a fighter base for P-51s to escort B-29s to Japan and an emergency landing field for crippled B-29s. Airfield #1 was ready for observation aircraft by 26 February 1945 and for transport aircraft from 3 March. Eventually Airfield #1 had a 6000' (1830 meter) fighter strip; Airfield #2 had a 6000' (1830 meter) fighter strip and two 8500' (2590 meter) bomber strips; and North Field had a 6000' (1830 meter) fighter strip. The bomber strips of Airfield #2 were later extended to 9400' (2865 meters) and 9800' (2990 meters). Four 1000-gallon (3785 liter) gasoline tanks were set up and supplied with a pipeline allowing fuel to be pumped into the tanks directly from offshore tankers. Because the island was plagued by low cloud due to the sulfur in the air, Iwo Jima was among the first air bases to receive ground control approach radar.

An attempt to construct a sheltered anchorage on the southeast coast with breakwaters and block ships was unsuccessful, and supplying adequate fresh water remained problematic.

Some 2,251 B-29s and 24,761 aircrew made emergency landings by the time of the Japanese surrender.

Image Gallery


Maps of Iwo Jima landing operation

USMC

Iwo Jima under bombardment

USMC

Aerial view of Suribachi

U.S. Navy

Landing craft coming ashore on Iwo Jima

USMC

Beach terrace behind Red Beach 1

USMC

Mount Suribachi

USMC

Wreckage on the beaches

USMC

Marine attacks sand-covered bunker with flamethrower

USMC

Engineers probing for mines

USMC

The first flag goes up atop Suribachi

U.S. Navy

Motoyama Plateau

USMC

First B-29 on Iwo Jima

USMC

Marine infantry and tanks advancing

USMC

Marine command post taking cover in a gully

USMC

Japanese bunker overlooking East Boat Basin

USMC

Dug in tank

USMC

Knocked-out gun position on Iwo Jima

USMC

120mm AA gun on Iwo Jima

USMC

References

Drea (2009)

Gilbert (2001)

Leckie (1962)
Morison (1953, 1959)
Rottman (2002)
Spector (1985)

Tillman (2010)

Venzon (2003)

Wheeler (2007)


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