Why Japanese Commanders Couldn’t Explain How Marines Took Iwo Jima in 36 Days… D

Eight square miles of volcanic rock, no fresh water, no cover, no beach worth the name, and 22,000 Japanese soldiers who had spent eight months digging 17 miles of tunnels into the island’s bones, waiting. The United States Marine Corps landed 70,000 men on Iwo Jima on February 19th, 1945, and what followed was 36 days of combat so dense and so costly that the Marines took more casualties on that single island than they had in the entire four years of the First World War. When it was over, Japanese commanders in Tokyo sat in silence trying to understand how it had happened. They had built what they believed was an impenetrable fortress. They had positioned every gun, every tunnel, every fighting position to make the cost of taking the island prohibitive. They believed the Marines would break. This is No Man’s Land. If you are new here, hit subscribe

and turn on notifications. New documentaries go up every single week. To understand why Japanese commanders could not explain what happened on Iwo Jima, you have to understand what they believed they had built. Lieutenant General Tadamichi Kuribayashi arrived on Iwo Jima in June of 1944 and immediately recognized that the island could not be held in the conventional sense.

He had served as a military attaché in Washington in the 1930s. He had driven across the American interior, visited Ford’s factories in Detroit, studied American industrial capacity first hand. He knew with a clarity that very few Japanese officers possessed what the United States was capable of producing and delivering to a battlefield.

He knew that a conventional surface defense, the kind the Japanese had used on Tarawa and on Peleliu and on Saipan, would be destroyed by American naval gunfire and air bombardment before the Marines ever came ashore. So, he abandoned the doctrine. He told his commanders that they would not meet the Americans on the beaches.

They would not waste men in banzai charges that looked heroic on paper and accomplished nothing in practice. Instead, Kuribayashi ordered his engineers to dig. For 8 months, around the clock in shifts, 22,000 Japanese soldiers excavated the volcanic rock of Iwo Jima with hand tools, pneumatic drills, and explosives.

They built 17 miles of tunnels connecting hundreds of reinforced bunkers, artillery positions, and fighting caves. They built hospitals underground. They built command posts 40 ft below the surface. They built ammunition magazines sealed into the rock with steel doors. They positioned every weapon to create overlapping fields of fire across every possible approach to the island.

The beaches were not defended because the beaches were a trap. The real defense began 200 yards inland where the tunnels emerged into firing positions that no amount of naval gunfire could destroy without physically blasting open every square yard of volcanic rock on an 8-square-mile island.

Kuribayashi told his men they would each kill 10 Americans before they died. He did not tell them they would live. He had a plan designed to make taking Iwo Jima so costly that the American public would demand a negotiated peace before the invasion of the Japanese home islands could begin. The American commanders who planned the invasion of Iwo Jima knew it would be difficult.

They did not know it would be what it was. The pre-invasion naval bombardment that hit Iwo Jima was the heaviest laid down on any target in the Pacific War up to that point. For 3 days, American battleships, cruisers, and destroyers fired approximately 22,000 shells into an island 8 miles long and 4 miles wide.

American aircraft dropped thousands of tons of bombs. The ground itself shook so continuously that observers on the ships reported seeing the entire island vibrate with each salvo. Marine commanders watching from the transports believed the bombardment must have destroyed or suppressed a substantial fraction of the Japanese defenses.

They had learned that lesson in blood on a dozen islands across the Pacific, but even they, even the men who had survived the nightmare of Tarawa’s beaches and the grinding horror of Peleliu’s ridges could not fully anticipate what Kuribayashi had built. When the first waves of Marines hit the beaches on the morning of February 19th, the first thing they noticed was the silence.

There was no Japanese fire. The beach was almost quiet. Men looked at each other across the black volcanic sand and began to move inland. For approximately 30 minutes, the landing was almost unopposed. Some Marines later said they thought the bombardment had actually worked, that maybe this one would be different.

Then Kuribayashi gave the order. Every gun on the island opened simultaneously. The Marines on the beach, pinned between the water and the rising volcanic terraces, had nowhere to go and no cover that could stop what was falling on them. The battle had not begun.

It had sprung fully formed from the earth. The black volcanic sand of Iwo Jima was unlike anything the Marines had encountered on any previous island. It was not sand in the way soldiers understand sand. It was loose volcanic ash and pumice, ground fine over centuries, that shifted and collapsed under weight like wet gravel.

Marines trying to dig a fighting hole watched the walls cave in before they could get below the surface. Men running for cover found their legs sinking into the ground with each stride as if the island were trying to swallow them. Tanks that made it off the landing craft immediately bogged down in the volcanic matrix, treads spinning uselessly in the collapsing material.

The terrain that Kuribayashi had chosen to defend was not just fortified. It was actively hostile to the men trying to take it. The volcanic activity that made Iwo Jima so strategically important also made it one of the least hospitable places on earth. Steam vented from cracks in the ground.

The soil in places was hot enough to cook food. Men who dug fighting positions in the wrong areas found themselves unable to stay in the holes because of the heat rising from the volcanic rock beneath. There was no fresh water anywhere on the island. Every drop the Marines consumed had to be brought ashore from the ships.

In the first days of the battle, under constant fire, with the landing beaches clogged with men and equipment and the dead and wounded, the simple act of moving 200 yards inland took the better part of a day and cost dozens of casualties. The Japanese had understood all of this when they chose Iwo Jima as the place to make their stand.

The terrain was not an obstacle to their defense. It was part of their defense. Every step the Marines took cost something and the island itself was extracting payment before the Japanese had fired a single shot. The feature of Iwo Jima’s defense that most confounded American commanders, both during the battle and afterward, was the tunnel network.

On every previous island the pattern had been recognizable. Marines who fought their way through a bunker complex, killing every defender they could find, would advance 100 yards and then come under fire from positions they had already passed. Japanese soldiers who had retreated through the tunnel system had reoccupied positions the Marines believed were cleared.

This happened on the first day. It happened on the 10th day. It happened on the 30th day. Barely large enough for a man to crawl through, invisible in the darkness until someone fell into it. American engineers eventually developed a systematic approach to destroying the tunnels.

Flamethrower teams sealed the entrances with fire. Demolition teams packed explosives into every opening they could find and collapsed the passages. But, the tunnels were deep and extensive and numerous. And, for every passage the Marines destroyed, there were others they had not found yet.

Kuribayashi had built a fortress that existed in three dimensions, and the Marines were fighting in two. On the fifth day of the battle, Marines of the 28th Regiment reached the summit of Mount Suribachi, the extinct volcanic cone that dominated the southern end of the island, and raised an American flag.

A photograph of the second flag raised that morning became the most reproduced photograph in the history of American journalism, and one of the most iconic images of the 20th century. What the photograph did not convey, and what is essential to understanding the battle, is that raising the flag on Suribachi was not the end of the fight.

It was the end of the beginning. Suribachi represented approximately 10% of the island’s land mass. The remaining 90%, including the bulk of Kuribayashi’s tunnel network, all three of the airfields, and the vast majority of his 22,000 defenders lay to the north. The flag went up on day five.

The battle lasted 31 more days after that. The Marines who watched the flag rise from positions on the beach did not celebrate for long. They could hear the fighting continuing on the plat- teau above them. They knew what was ahead. The American press treated the flag raising as a turning point because turning points make better stories than the grinding reality of what actually followed.

What actually followed was 22 miles of terrain that Kuribayashi had converted into an interlocking system of killing ground so dense that in some sectors the Marines gained ground measured in yards per day. Senior Marine commanders watching the battle from offshore described a quality of Japanese resistance unlike anything they had encountered previously.

Not the suicidal banzai charges of the early Pacific war, which had been terrifying but ultimately wasteful of Japanese lives and ultimately beatable. This was something more methodical, more patient, more coldly rational. Kuribayashi’s men were not dying for the emperor in the old way.

They were dying for every square yard of rock one at a time, taking as many Marines with them as the terrain and their positions and their remaining ammunition would allow. The element of the Marine assault that most confounded Japanese defenders at every level, from the men in the tunnels to Kuribayashi and his command post, was the speed at which the Americans regenerated.

Japanese tactical planning had been built around the concept of attrition. This had worked in China. It had worked in Southeast Asia in the early years of the war. Was the logistical system that the American military had built to sustain combat operations across the Pacific.

When a Marine rifle company took 50% casualties in a single day, which happened repeatedly during the Iwo Jima campaign, replacements arrived the following morning. Not raw recruits who had never fired their weapons in combat, but trained Marines who had been moving forward through the supply chain specifically to feed into units that needed them.

The artillery that the Marines brought ashore was sufficient to devastate almost any fixed defensive position on earth, and they brought it ashore continuously through the surf and the volcanic sand and the Japanese fire, and they kept it firing. The medical system that evacuated the wounded back to hospital ships offshore and returned men to the line within days of minor wounds kept the effective strength of Marine units higher than any purely human calculation of the violence they were absorbing would have suggested was possible. Kuribayashi wrote in his dispatches to Tokyo in the second week of the battle that the Americans were not behaving the way the doctrine said they should. They were taking losses that should have broken a force of their size and they were continuing to attack. He reported this not with alarm but with a kind of professional admiration for an enemy that was refusing to function according to the rules his training had taught him to expect. The weapon that ultimately broke

the tunnel system on Iwo Jima was not artillery. It was not naval gunfire. It was not the explosive charges that Marine engineers spent the battle packing into every cave entrance they could find. It was fire. The M4 Sherman tank modified to carry a flamethrower known to the Marines as the Ronson or the Zippo was the single most effective weapon system in the Iwo Jima campaign and the Japanese had no answer for it.

The tank flamethrower could project burning fuel 60 yards and sustain the flame long enough to fill an enclosed space completely. For a bunker or a cave system, this was not simply a weapon. It was a death sentence for everyone inside regardless of how deep the tunnel went, regardless of how many turns it made, regardless of how many men were sheltering there.

The heat and the oxygen deprivation and the burning fuel followed the tunnels. Japanese soldiers who survived Iwo Jima described the arrival of the flame tanks as the single most psychologically devastating experience of the campaign. They could hear the tanks above them. They could feel the ground shake and then the fire came down the tunnel entrance and there was nothing to be done.

Regular Marine rifle platoons had learned through brutal trial and error in the first week of the battle that assaulting a bunker with infantry meant losses that the unit could not sustain. A single Japanese machine gun position in a reinforced cave could hold off a platoon for hours and kill a third of it in the process.

The flame tank changed the calculation entirely. The Marine infantry now moved to protect the tank and suppress the positions that could destroy it, while the tank did the actual work of clearing the position. It was slower than a conventional assault, and it required intense coordination under fire, but it worked.

And the Japanese, for all of Kuribayashi’s genius for adaptation, had no countermove. The battle for Iwo Jima lasted 36 days. When it was declared secure on March 26th, 1945, the cost on both sides was nearly incomprehensible. Of the approximately 70,000 Marines who participated in the campaign, nearly 27,000 were killed or wounded.

6,821 Americans died on Iwo Jima. It remains to this day the bloodiest battle in the history of the United States Marine Corps. Of the 22,000 Japanese defenders, fewer than 220 survived to be taken prisoner. The rest died in the tunnels and the bunkers and the caves and the ruins of Kuribayashi’s underground fortress, exactly as he had told them they would.

Kuribayashi himself sent his final radio message to Tokyo on March 17th, 9 days before the battle officially ended, reporting that his forces were reduced to a remnant and that organized resistance would shortly cease. His body was never found. The island that had cost all of this was, by any conventional measure of military real estate, worthless.

8 square miles of volcanic rock with no agricultural value, no mineral wealth, no population, no strategic depth. What it had was location. Iwo Jima sat almost exactly halfway between the Mariana Islands, where the B-29 bomber bases were located, and the Japanese Home Islands.

American fighter aircraft flying from Iwo Jima could escort the B-29s to Japan and back. Crippled bombers that could not make it back to the Marianas could land on Iwo Jima’s airfields. In the months between the capture of the island and the end of the war, approximately 2,400 B-29 sorties made emergency landings on Iwo Jima.

At a standard crew of 11 men per aircraft, that is a potential 26,400 American airmen who were alive at the end of the war because there was an airfield on Iwo Jima to land on. In the weeks after the battle, as American commanders reviewed the campaign and Japanese survivors gave their accounts and the intelligence reports filtered back to Washington and Tokyo, a consensus emerged about what Kuribayashi had accomplished and why it had ultimately failed.

He had built the most sophisticated static defensive system the Imperial Japanese Army ever deployed in the Pacific. He had discarded the suicidal banzai doctrine that had wasted Japanese lives on a dozen previous islands to no tactical benefit. He had understood that the Americans could not be beaten in a stand-up fight and had designed a defense intended not to win, but to make winning so expensive that American political will would erode before the invasion of Japan.

He was right about almost everything except one thing. He had been right that conventional surface defenses would be swept away by American firepower. He had been right that banzai charges were tactically useless. He had been right that the tunnel system would force the Marines to fight for every yard.

What he had not correctly accounted for was the institution he was fighting. The United States Marine Corps had been built over decades and across the entire Pacific campaign specifically to do what it did on Iwo Jima, to assault fortified positions across open ground under fire and keep moving regardless of casualties.

It was not that the Marines were individually more capable soldiers than Kuribayashi’s defenders who fought with a discipline and a ferocity that earned the genuine respect of the men who killed them. It was that the Marine Corps as an institution had been optimized for exactly this kind of battle and Kuribayashi’s defense for all its ingenuity was ultimately a problem that the institution had been designed to solve.

The Marines took 36 days. Kuribayashi had hoped for months. The difference in the end was not firepower. It was not technology. It was what the Marine Corps had built itself to be over 40 years of preparation for exactly this moment. 22,000 Japanese soldiers built a fortress inside a volcano.

They tunneled 17 miles through solid rock. They positioned every gun to make landing on that island as close to impossible as any military force had ever made any objective. The Marines took it in 36 days. The Japanese commanders in Tokyo who read Kuribayashi’s final dispatches understood what had happened but not why.

They never fully understood why. This is no man’s land. If this video meant something to you, hit the like button. It is the single best way to push this story to someone who needs to hear it. Subscribe if you are not already here and drop a comment telling us where you are watching from.

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