Background to the invasion
On 19 February 1945, 72,000 United States Marines of the 3rd, 4th and 5th Divisions launched an amphibious attack on the small island of Iwo Jima some 660 miles south of Tokyo; their objective was to neutralise the three airfields on the island and to secure a forward base for the B-29 Superfortress bombers of the 20th Air Force operating from the islands of Guam, Saipan and Tinian in the Marianas.
On October 1944 the Marines had been directed to prepare for this assault that was to be sandwiched between MacArthur's Philippines campaign and the occupation of Okinawa scheduled for April 1945. The planners contemplated a battle lasting some ten days. Instead it became the Corps' bloodiest engagement ever in which nearly 6,000 Marines were killed and more than 20,000 wounded. It was a grim struggle of attrition that dragged on for over five weeks and inspired Admiral Nimitz to declare, 'On Iwo Jima, uncommon valour was a common virtue.'
The American viewpoint of the battle is well documented, but the Japanese perspective is much less familiar, largely because there were only around 1,100 survivors from an estimated garrison of over 21,000, and many of these were Korean labourers who did not share the Japanese determination to fight to the death.
By the end of 1944 the Japanese had been rolled back to the limits of their defensive perimeter around the homeland. The glory days of conquest at Pearl Harbor, Singapore and the Philippines almost forgotten as they faced defeat on all fronts.
General MacArthur's X and XXIV Army Corps had landed in the Philippines in October 1944 and were storming through the island of Luzon. Nimitz's Marines were pursuing their 'island hopping' campaign, which had started at Tarawa in 1943 and had now engulfed the Marshall Islands, Peleliu and the Marianas. The Task Forces of the US Navy, now the largest the world had ever seen, roamed at will throughout the Pacific.
In early 1945 therefore Japan was almost isolated, her Empire reduced to a number of far-flung garrisons in Korea, the Dutch East Indies, Indochina (Vietnam), and Manchuria. Also, because of the overwhelming Allied naval presence in the Pacific, all of these units were virtually cut off as the Japanese had neither the ships to transport them home nor the naval forces to protect them. The only unit that was not isolated was the Kwantung Army in Manchuria, but even that had been denuded of its best elements over the years to reinforce the Solomon Islands, Peleliu and the Marianas.
The internecine nature of Japanese military society ensured that the truth of the war situation was scarcely known, even between the army and navy at the highest level. The huge naval losses at Midway, the Philippines Sea and Leyte Gulf were minimised to such an extent that the army did not know that the navy had virtually no seagoing vessels available other than submarines, and that their air arm consisted largely of Kamikaze suicide units.
However, the military were still fiercely pursuing a policy of fighting to the death rather than surrendering and accepting disarmament. The professional army and naval officers could not envisage a defeated Japan in which they would be redundant and they were well aware that the Allied surrender terms would categorically state that Japanese militarism should be eliminated.
As the Americans drew closer, the strategic importance of Iwo Jima became increasingly apparent — one of the Volcano Islands, Iwo Jima (Sulphur Island) lay near the end of the Nanpo Shoto, a chain of islands stretching some 750 miles into the North Pacific from Tokyo Bay.
A small military force had been in place in the area since 1914 when the General Staff decided to fortify Chichi Jima in the nearby Bonin Islands, and by 1941 when America and Japan went to war the garrison stood at 1,400, mostly naval personnel.
By 1943 the first airfield had been constructed on Iwo Jima and around 1,500 naval airforce staff and 20 aircraft were in place. But it was not until the Marines invaded the Marshall Islands in early 1944 that Japanese Imperial Headquarters realised that their inner line of defence — the Carolines, Marianas and Volcano-Bonin Islands — were threatened. Then the 31st Army was organised on Saipan under Lt. Gen. Eiryo Obata with overall responsibility for the whole area. In March and April of 1943 the build-up of army and naval units on Iwo Jima began in earnest.
Obata was to die during the American invasion of the Marianas and his whole 31st Army was virtually annihilated. The Japanese strategists now knew that the homeland was now vulnerable to massive attacks from US bombers and that Iwo Jima would be a prime target for the next Marine assault.
Defence of the island
In May 1944, the Japanese Prime Minister, Hideki Tojo, summoned General Kuribayashi to his office and informed him that he was to be the new commander of Iwo Jima. Kuribayashi was highly regarded by the Japanese General Staff and favoured by the Emperor, having previously been commander of the Tokyo Guard whose responsibilities included the protection of the Emperor and the Imperial Palace, However, he was virtually unknown to the US commanders and this may have led to a certain amount of complacency on their part for which they were to pay dearly in the coming battle.
Many other staff officers of the Imperial Japanese Army could lay claim to more combat experience, but despite this limitation Kuribayashi proved to be Japan's most outstanding army commander of the war. His Iwo Jima campaign can be justly regarded as a classic of defensive strategy, Lt. Gen. Holland 'Howlin' Mad' Smith, Marine Corps commander of Expeditionary Troops during the battle was to dub him 'our most redoubtable adversary'.
It is not difficult to imagine the General's feelings about the appointment. He had followed the progress of the war with growing dismay and was well aware that a successful defence of Iwo Jima was impossible. 'Do not plan for my return' he wrote to his wife as he assumed his new command.
It was obvious to him that the standard tactic of attempting to halt the invader on the beaches did not work This was even the case at Tarawa, where large numbers of the Marine's landing craft ground to a halt on the reef hundreds of yards offshore, forcing the invaders to wade to the beach in the face of devastating fire.
The General had studied the battle for Peleliu and approved of the tactics used by the commander, Lt. Gen. Inoue, who had led a fighting withdrawal to prepared positions in the Umurbrogol Hills. 'Take advantage of the terrain and carry out strong counter attacks from previously planned and prepared positions,' wrote Inoue in a chilling preview of the methods that were soon to be adopted by Gen. Kuribayashi.
Upon his arrival in June 1944, the General was to find rivalry and dissension between the army and navy units on the island. Kuribayashi had been given a free hand by Tokyo to organise the Iwo Jima defences as he saw fit and he soon impressed upon his officers that he would not tolerate insubordination He emphasised this by sending back to the mainland a number of officers he considered to be uncooperative. Along with them went the civilian population of the island as he felt that they could serve no useful purpose and would be a drain on the limited food and water supplies.
The garrison strength was dramatically increased, the three principal units being the 109th Division under the General, the 2nd Mixed Brigade under Maj. Gen. Senda and the Naval Landing Force under R. Adm. Ichimaru.
Iwo Jima was divided into five sectors. All but the Mt Suribachi area would be directly controlled by the General, leaving the volcano and its 200 men as an independent command under Colonel Atsuji. Kuribayashi was aware that the volcano was the most vulnerable part of the island, with only a half-mile-wide isthmus joining it to the rest of the island, but its loss on the fifth day of the battle was still an unexpected and bitter blow.
The General had finalised his strategy soon after inspecting the island. He would concede the beaches to the Marines and concentrate on in-depth defences, mainly in the north of the island, with masses of rocks, gullies, caves and valleys. He forbade the traditional 'banzai' attack, which he considered to be pointless and stupid, preferring a drawn-out battle of attrition in which he hoped to inflict such severe losses on the enemy that they would have second thoughts about invading the Japanese mainland. Kuribayashi's propositions flew in the face of traditional army and navy dogma and bitter arguments raged both on Iwo Jima and in Tokyo. In the end he was forced against his better judgement to compromise and start to construct 135 pillboxes facing what were now accepted as the obvious landing beaches between Mt Suribachi and the East Boat Basin — the fact that all of them were overrun by the Marines within the first three hours of the invasion adds credence to the General's original plan.
One of the most remarkable features of the Iwo Jima defence system was the underground tunnels. Being a volcanic island, the sub-strata was made up of soft pumice-like rock that could be easily worked with hand tools and combined well with cement to form an ideal mixture for the reinforcement of gun positions and pillboxes. Work progressed at a furious pace and a system of underground fortifications was constructed the likes of which have never been seen in the history of warfare. Thousands of yards of tunnels were built in the run-up to the invasion connecting all major defence posts and observation positions. Command posts, underground supply and ammunition dumps were positioned together in their own network with medical posts and rest areas. Digging the tunnels was extremely tiring: the troops were only able to work for up to ten minutes at a time wearing gas masks because of the sulphur fumes.
Maj. Yoshitaka Horie had been sent to Iwo Jima in June 1944 to become a member of General Kuribayashi's staff and was a witness to the tunnelling and construction work going on all over the island. He was later transferred to Chichi Jima to organise the shipment of supplies to Iwo and thus survived the battle and the war. His observations form a unique account of events leading up to the American invasion.
'In October he began to make pillboxes using several battalions every day but when American forces landed he had scarcely completed them,' said Hone, who was in agreement with the General about giving priority to the defence of the north of the island. 'The airfield [No. 1] was trodden by American forces in only two days. If we had infused this great strength, many materials and three months of labour which were used on the airfield into the defence of Motoyama district and Mount Suribachi we would have been able to make these areas much stronger.'
The Assault
At 6.30 am on Monday 19 February 1945, Adm. Richmond K. Turner issued the order 'land the landing force' and the first Amtracs headed for the six designated landing beaches between Mount Suribachi and the East Boat Basin on the southeast coast of the island. Although the Marines encountered a brisk bombardment as they approached the shore the Regimental commanders were not unduly worried; messages of 'light resistance' and 'moderate mortar fire' flashed to the navy support ships and they were confident that the massive bombardments from the offshore battleships and swarms of carrier-based aircraft were neutralising the Japanese defences.
In reality Kuribayashi was biding his time, he wanted the enemy ashore and on to the central plateau before he unleashed his massive and well-rehearsed artillery and mortar barrages; but fate was to provide him with an even more tempting scenario.
As the Marines stormed out of their landing craft they encountered terrace upon terrace of soft black volcanic ash, some up to l4 ft high. Men struggling under heavy loads of equipment sank up to their knees and vehicles immediately bogged down as the construction battalions, the Seabees, unloaded their bulldozers and attempted to clear a passage up to the firm ground on the plateau. The condition of the beaches had been described by the planners as 'excellent' with 'an easy approach inland'. Fortunately for these desk-bound warriors they did not have to be there to verify this.
As successive waves of landing craft arrived, the log jam of men and materials became an irresistible target and the General brought his artillery and mortar batteries, located on Mt. Suribachi, the quarry above the East Boat Basin and around the eastern perimeter of airfield No. 1, to bear on the crowded beaches. Casualties mounted alarmingly as the Japanese gunners, with ranges worked out to the nearest yard from months of practice, targeted the landing beaches to devastating effect. But, despite the pillboxes and minefields located between the beach and the airfield, the Marines surged forward to escape the hell at the waterside.
At the end of Green Beach where the sand terraces gave way to rocks and boulders at the foot of Mt. Suribachi, the 1st and 2nd Battalions of the 28th Regiment were able to press forward despite murderous fire from their left flank, and by early evening were across the isthmus effectively isolating the volcano.
The General had made what was possibly his only mistake of the battle — by not starting his bombardment sooner. Had he pounded the beaches as the first waves of assault troops arrived he may have caused even more mayhem than he already had.
The Japanese artillery barrage on D-Day revealed the location of many of their gun emplacements and for the next day and a half battleships and cruisers were to direct point-blank fire against them. The General reported 'Although we lost only 95 casualties the top of Suribachi disappeared by a quarter, all six reinforced concrete pillboxes on the southern coast were destroyed and eight navy flat-shooting batteries were destroyed. We also lost four 140 mm guns, four 120 mm guns, three 120 mm AA guns, one 80 mm AA gun, one 75 mm field gun, seven 25 mm machine guns, two trench mortars and two searchlight units.' These were serious and irreplaceable losses that were a foretaste of the major damage that would be caused by the navy ships circling the island. By the end of D-Day the Marines were across the island below Mt. Suribachi and inland around l,000 yds between the volcano and the quarry above the East Boat Basin. They were far short of the line designated as the target for the day, and they had suffered 2,400 casualties. Although the Marines had 30,000 men ashore by nightfall, Kuribayashi's defence had taken a much bigger toll than the most extravagant American predictions.
On D+1, with Mt. Suribachi isolated and the Seabees gradually clearing the invasion beaches of the masses of abandoned vehicles and landing craft, a steady flow of reinforcements, tanks and artillery began to come ashore as the fighting moved inland towards Airfield No. 1. The Marines' strategy was simple, cross the island below Mt. Suribachi and isolate it, then swing northward on a broad front with the 5th Division in the west, the 3rd in the centre, and the 4th in the east. The official Marine Corps history states: 'the Japanese were deeply entrenched in hundreds of excellently constructed positions — blockhouses, bunkers, pillboxes, caves and tanks. Masterful camouflage had prevented American ships and planes from detecting many of these positions, and of those that were spotted, as often as not a direct hit failed to put them out of business. Complete accomplishment devolved upon ground Marines.'
As the men of the 28th Regiment gathered their strength for the assault on Mt. Suribachi, the bulk of the fighting centred around the first airfield and by noon it was almost in American hands largely due to the deployment of Sherman M4 tanks. 'The enemy's tanks have strong destructive power, slow but steady advance,' said the General. 'If our anti-tank guns appear they retire quickly . . . at last came to the conclusion that bodily attacks with explosives was the only way to destroy it.'
The weather had deteriorated on the second day and the Marines on the island, more used to fighting in equatorial conditions, shivered miserably in their foxholes. By nightfall the whole of Airfield No. 1 had been taken, but the Japanese resistance had cost the Marines dearly: a further 1,000 were dead or wounded yet three-quarters of the island had yet to be occupied.
To the north, the Marines had reached the first of the Japanese cross-island defence lines short of airfield No. 2 and were just beginning to realise that they were up against a much larger garrison than they had estimated and a much more intelligent commander. Kuribayashi still had 8 Infantry Battalions, a Tank Regiment, 2 Artillery and 3 Mortar Battalions and the 5,000 gunners and infantrymen of Ichimaru's naval command. His Artillery commander, Col. Kaido, seemingly had the advantage over the enemy with his 150 mm howitzers and 120 mm mortars as the well-co-ordinated Marine attacks began to gradually disintegrate into vicious small-unit actions.
In the failing evening light, 50 Japanese kamikaze aircraft of the 2nd Milate Special Attack Unit from Katori Airbase, descended on the US Navy force surrounding the island. Two blazing aircraft slammed into the side of the aircraft carrier USS Saratoga causing serious damage which put her out of action for the rest of the war. Another ploughed squarely into the escort carrier USS Bismarck Sea causing huge explosions among the aircraft crowded on the flight deck and within a short space of time she rolled over and sank.
23 February, D+4, saw the Americans take Mt. Suribachi. Not only was this an important tactical victory but it assumed huge patriotic significance when Associated Press photographer Joe Rosenthal took his picture of Marines raising the Stars and Stripes on the summit in what proved to be probably the most famous photograph of World War II.
In the north, however, Gen. Kuribayashi's disruptive battle of attrition was working to plan. By forcing the enemy to come to him and fighting back from his underground network of tunnels and bunkers, he slowed the American advance to a crawl as the fighting degenerated into desperate small-unit actions. Demolition charges, flamethrowers, grenades and small arms were to be the only way in which the Japanese could be dislodged from their entrenched positions.
As the battle moved steadily northward the terrain became more and more rugged. The land around Airfields 2 and 3 gave way to valleys, hillocks and sheer cliff faces, and vicious battles erupted for the control of hills that were identified simply by their height (there were three Hill 362s on the island); while other features took their names from personalities or from their appearance. 'Cushman's Pocket', called after Lt. Col. Robert Cushman, 'Turkey Knob', and the 'Amphitheatre' were all in a complex to the east of the airfields that was aptly named 'The Meatgrinder'.
Each day's attack began to take on a predictable pattern. A massive artillery bombardment of the Japanese front, supplemented by naval gunfire and air attacks when the weather permitted, was followed by Marine infantry with tank support. The Japanese countered by simply withdrawing into the depths of their caves and tunnels to sit out the bombardment, re-emerging in time to man the masses of strongpoints and forcing the enemy to come to them.
By 1 March American casualties had become critical and combat efficiency plummeted. Unit commands sometimes passed from Captain to Lieutenant to Sergeant and even to Pfc, and the Divisional Commanders were scathing of the quality of the replacements. 'They get killed the day they go into battle', said Gen. Erskine of the 3rd Division. Kuribayashi had no such worries, his men knew that they would never leave the island alive and were resigned to their fate. But unlike the Americans, as their numbers dwindled there was no hope of securing replacements.
Iwo Jima began to take on a bizarre appearance. In the north the artillery thundered, tanks lumbered among the valleys and gorges and men died in their hundreds. In the south a small city of Nissen huts, hospitals, cookhouses and tents appeared as the Seabees lengthened and expanded Airfield No. 1 to accommodate the bombers and fighters of the 20th Air Force; on 4 March the first B-29 Superfortress 'Dinah Might', made a successful emergency landing.
By D+18 the Marines broke through to the north coast of the island and Kuribayashi's forces were split in two. The General remained in the northwest gradually withdrawing to an area just south of Kitano Point. In the east fighting continued in the 'Meatgrinder' until Gen. Senda's garrison finally succumbed to overwhelming numbers and firepower. In a battle that would be remembered for its ferocity, the final phase reached heights of savagery that shocked even battle-hardened veterans. Entrenched in an area called 'The Gorge', a mere 700 yds long and 500 yds wide, the General and his men lasted for a further week against flamethrower tanks and massive Marine Corps infantry attacks. Kuribayashi radioed Chichi Jima, 'I have 400 men, the enemy besieged us by firing and flame from their tanks. The enemy's front line is 300 metres from us. They advise us to surrender by loudspeaker but we only laugh at this childish trick'.
The cost of the battle
In 36 days of combat Japan lost over 20,000 soldiers and sailors. The circumstances of General Kuribayashi's death are not known for certain. Some sources say that he killed himself but his son Taro maintains that he was killed by shell fire and was buried at the foot of a tree by his men. He was given this information by a Sgt. Oyama who was with the general at the time and was later taken prisoner when wounded.
In America doubts were raised over the huge human cost for what was described as 'seven square miles of useless real-estate'. But in the period from 4 March until the end of the war 2,200 aircraft made emergency landings on Iwo Jima, a figure representing over 22,000 aircrew, who would probably have perished in the vast areas of ocean between the Marianas and the Japanese mainland.
The Marines fought a gallant battle to secure the island, suffering casualties of 5,885 dead and 17,272 wounded. 27 Medals of Honor were awarded, more than a third of the Marine Corps total for the entire war. For the US High Command the battle was a horrific indication of what was in store in the upcoming invasion of the Japanese homeland where every city, town, village and field would be defended to the death by both the armed forces and the civilian population. Happily for the Americans the dropping of the atom bombs on Hiroshima and Nagasaki would make such an invasion unnecessary. Gen. Tadamichi Kuribayashi proved to be Japan's outstanding army commander of the war. Fighting a masterful battle of attrition he exacted a frightening toll of the Marine invaders even though he knew that he was doomed from the start. The US Marines gave him the accolade of 'the best damn General on this stinking island'.
Further Reading
Alexander. Col. Joseph H, Closing In — Marines in the seizure of Iwo Jima (Marine Corps Historical Center, Washington DC, 1994)
Bartley, Whitman S., Iwo Jima — Amphibious Epic (HQ, Marine Corps, 1954)
Ross, Bill D., Iwo Jima — Legacy of Valour (Random House, NY, 1986)
Wheeler, Richard, Iwo (Lippincott & Crowell, NY, 1980)
Wright, Derrick, The Battle for Iwo Jima 1945 (Sutton, 1999)
Wright, Derrick, Campaign 81: Iwo Jima 1945 The Marines raise the flag on Mount Suribachi (Osprey, 2001)
by Derrick Wright