Iwo Jima is a tiny1 volcanic island located about 660 (1,121 km) miles South of Tokyo and about 625 miles (1,062 km) North of Saipan, between the Marianas Islands and Okinawa. It is part of the Bonin chain of islands, south of the main Japanese island of Honshu.
The name Iwo Jima translates as Sulphur Island, which is appropriate due to the underground sulphur springs, which produce fumes that permeate the air though ground vents scattered throughout the island. The shape of the island, as seen from the air, has been described as that of a pork chop.
The only notable landmark on this almost completely barren island is Mt Suribachi, a 556-foot (169-metre) volcanic cone on the southern tip. Coarse black sand and rocky cliffs make up most of the remainder of the island, which rises suddenly from the Pacific Ocean2. Iwo Jima has no source of drinkable water.
Why it Was Important
Iwo Jima held both symbolic and military importance for the Japanese forces during World War II.
The symbolic importance was in the fact that Iwo Jima was considered Japanese home soil, administered by the Tokyo metropolitan government. No foreign army had set foot on Japanese soil in 4,000 years. Additionally, the loss of Iwo Jima would mean that the battle for Okinawa, and the invasion of Japan itself, was not far off.
The military importance was due to the island's size, location and geography. It was one of the very few islands in that part of the Pacific Ocean whose terrain would accommodate aircraft runways. The Japanese had built three airfields and were using Iwo Jima as a base for Kamikaze attacks and for air attacks on the US-controlled Marianas bomber bases. Without Iwo Jima, the Japanese air forces would have to operate from Okinawa or Kyushu.
Because of this symbolic and military importance, Japan had 23,000 defenders on the island.
To the United States
The United States wanted far more than simply to deny Japan the use of the Iwo Jima airbases. In the hands of the US, the airbases there would provide a base for protective fighter escorts to accompany the newly-developed B-29 superfortress bomber planes, which had been striking mainland Japan from bases on the Micronesian island of Tinian. The 1500-mile (2410 km) trip was at the outer edge of the B-29's range. With Iwo Jima in US hands, damaged aircraft or aircraft that were low on fuel would have a place to land, instead of having to ditch in the Pacific Ocean.
The seizure of Iwo Jima would also allow the United States to enhance the existing submarine blockade of Japan with surface and air support, and give the United States the ability to conduct intensive air bombardment and to destroy what was left of Japan's air and naval capabilities.
The initial strategy for the taking of Iwo Jima by US forces called for the traditional 'softening up' of the Japanese defenders through aerial bombing followed by the taking of the island by storm with a strike force of 74,000 US Marines. The first carrier raids against Iwo Jima had started in June 1944. Concentrated bombing raids began more than two months before the US landing force was to be deployed. According to Admiral Nimitz, Commander in Chief, Pacific Command, 'No other island received as much preliminary pounding as did Iwo Jima'.
The Marines charged with taking Iwo Jima requested 13 days of continuous shelling from US naval forces before their landing. Because the island had already been the target of heavy bombing and because naval forces had been committed to MacArthur's campaign in Luzon, only three days of continuous shelling were granted. For those three days, six American battleships launched a barrage unparalleled in the war effort to date.
At about 2am on 19 February, 1945, shelling from the US Navy intensified. An hour later, artillery fire stopped. Iwo Jima was smoking as if the entire island was on fire. That wasn't the end of the pre-landing punishment inflicted on the island, though. A force of 110 bombers came next, bringing further destruction with them. Upon their departure, the naval shelling resumed.
In all, 6800 tons of bombs and 22,000 shells were dropped on Iwo Jima before the land invasion started.
The assault on Iwo Jima was to have been the 'ultimate storm landing'. Of the 110,000 US soldiers who had sailed to Iwo Jima in 880 ships over the previous 40 days, 74,000 Marines made up the original strike force, making this the largest concentration of Marines in any battle of World War II to date.
The operation was under the overall command of Admiral RA Spruance, Commander of the Fifth Fleet. Vice Admiral RK Turner was the Joint Expeditionary Force Commander and Lieutenant General HM Smith, USMC, commanded the Expeditionary Troops.
At 8:59am, US Marines from the Third, Fourth, and Fifth Divisions landed on Iwo Jima. The sandy soil, composed mostly of volcanic ash, was all but impossible for the Marines, with their 100-pound (45.5 kilo) packs, to climb through. The nature of the soil and the difficulty it represented had not been considered before the invasion.
General Kuribayashi, the Japanese Commander of Iwo Jima, devised a strategy that virtually all military historians agree was brilliant.
Kuribayashi had no expectation that he or any of the men under his command would survive. In a letter to his wife, written long before the invasion started, he advised her that she 'must not expect my survival'. His goal was for each Japanese soldier to kill at least ten Americans before being killed himself, making American causalities so high that the United States would be extremely hesitant to launch an attack on mainland Japan. With that objective in mind, Kuribayashi implemented a strategy that the United States had never seen the Japanese military use before.
On Iwo Jima there was to be no defence of the beach line and no frontal suicide attacks. Kuribayashi built a network of tunnels and underground bunkers so extensive that the Japanese army was able to fight almost entirely from underground. There were hidden interior positions dug into strategic locations throughout the island, especially in Mt Suribachi. Some 1500 rooms, connected by miles of tunnels, were dug into Iwo Jima3. This tunnel network was accessible through about 5000 pillboxes and caves. General Kuribayashi's command centre had walls 5 feet (1.5 metres) thick, a roof that was 10 feet (three metres) thick and was located beneath 75 feet (23 metres) of solid rock. Underground facilities included a hospital, a sauna and a seven-storey interior structure used by the Japanese for stockpiling weapons, ammunition, radios, fuel and rations.
From their fortified positions in Mt Suribachi, Japanese machine gunners had a clear view of every bit of the landing areas, which were also flanked by blockhouses and pillboxes. In short, the American forces discovered that the aerial pounding the island had taken had done only minimal damage to the Japanese fortifications and that, while they could not even see their enemy, that enemy, some 23,000 strong, could clearly see them.
The Battle Begins
Initially, the Marines met little resistance. That lasted for about 15 minutes.
At 9:15am, The Japanese forces started a mortar barrage against the US Marines. Anti-tank mines proved effective against the landing vehicles that were being used to deliver the Marines to shore. Every Marine, everywhere on the island, was within sight of Japanese guns. As long as the Japanese held Mt Suribachi, they could fire on any position the Marines established.
There were no front lines. The Marines, above ground, rarely saw a living Japanese soldier. The Japanese had no such problem seeing the Marines. After the first day of fighting, 566 American men were killed and 1755 more were wounded.
The Deadliest Battle
The importance of Iwo Jima can be measured by the troop concentration there. For the 36 days the battle lasted, that tiny island was the most densely populated place on Earth, occupied by some 80,000 US Marines and 23,000 Japanese soldiers. This importance, to both sides of the conflict, led to the battle for Iwo Jima becoming one of the deadliest in the history of warfare.
By the end of the first day, the Marines had not captured even half of their first objective, Mt Suribachi. The 30,000 Marines who had made it ashore by that point had succeeded in isolating the mountain and capturing part of one of the airfields, and were beginning to move inland. The attack of the American forces against the Japanese defences has been described as 'throwing human flesh against reinforced concrete'.
The fighting up the sides of Mt Suribachi was some of the most intense of the entire war. Japanese soldiers entrenched in the mountain had to be taken out by the use of flamethrowers and satchel charges. Close air support by Naval and Marine pilots was sometimes just a few hundred yards (metres) in advance of the Marines, who, in some cases, had to resort to using gasoline to set fire to ravines to force out the Japanese.
After four days of heavy fighting, American forces took control of Mt Suribachi, planting a United States flag at the summit. At 10:20am on 23 February, 1945, members of the 3rd Platoon, E Company, 2nd Battalion, 28th Marines, led by 1st Lieutenant Harold G Schrier, hoisted an American flag on a steel pipe, indicating that they had secured the mountain. Three hours later, another, larger, flag was raised. Associated Press photographer Joe Rosenthal, whose Pulitzer Prize winning picture of the six soldiers raising that flag was to become, arguably, the most recognized photograph to come out of World War II, captured this event on film by quickly snapping off a shot at the last second, having almost missed the entire event while talking with another news photographer. Ironically, this second flag was one that had been salvaged from Pearl Harbor, probably from a decommissioned destroyer or destroyer escort.
Mt Suribachi was, however, just one small part of Iwo Jima. The battle for control of the island would last over another full month, including a five day period in which the US Marines gained only 500 yards (460 metres) of territory. The battle for some of the smaller hills proved just as deadly as that for Mt Suribachi. Those smaller hills, which had to be taken by frontal assault, had been hollowed out and turned into huge blockhouses.
On 4 March, 1945, well before the island was secured, the first emergency landing was made on Iwo Jima by a B-29 bomber, which was repaired, refuelled and ultimately able to complete its mission.
Throughout most of the month of March, as the US military forces took control of Iwo Jima, bit by bit, they fought determined Japanese forces in front of them and those emerging from underground strongholds in areas thought to have been secured to their rear. By 11 March, the Japanese resistance was no longer centralised, fighting only in scattered pockets scattered across the island or using guerilla tactics from behind the American lines to attack US headquarters and disrupt communications.
It was not until 26 March, 1945 that the island of Iwo Jima was declared to have been secured. The battle that US military planners had expected to last a week or less ended successfully for the American forces 36 days after it had started.
With the exception of 1083 prisoners, the entire Japanese garrison of 23,000 men had been wiped out. Two of those prisoners did not surrender until 1951.
American losses included 6821 killed, 19,217 wounded and 2648 suffering from combat fatigue. Of the total 28,686 American casualties, 23,573 were members of the US Marine Corps. Over a third of the total Marines who participated in the invasion ended up being listed as casualties. About a third of all US Marines killed in action during World War II died at Iwo Jima, making that the battle with the highest number of casualties in Marine Corps history.
By their victory, the 3rd, 4th and 5th Marine Divisions and other units of the Fifth Amphibious Corps have made an accounting to their country which only history will be able to value fully. Among the Americans who served on Iwo Island, uncommon valour was a common virtue.
- Admiral Chester W Nimitz
The bravery with which the members of both military forces conducted themselves is beyond question. The Medal of Honor was awarded to 27 members of the US Marine Corps and US Navy for their actions at Iwo Jima and the ferocity with which the Japanese defended the island heavily influenced the later decision on the part of US leaders to use of the atomic bombs in Hiroshima and Nagasaki rather than to attempt an invasion of the Japanese mainland.
Was Iwo Jima Worth It?
Virtually all military historians agree that the battle for Iwo Jima was worth the price that the United States military had to pay. By the end of the war, 2400 B-29 bombers carrying 27,000 crewmen had made emergency landings on Iwo Jima and an additional 402 pilots who had fallen into the ocean were rescued by missions launched from there. The island became the home base for P-51 Mustangs and P-61 Black Widows which served as escorts and defenders for the B-29s which made bombing runs to mainland Japan. Iwo Jima became the first American base operating from inside the Japanese territory.