Their Backs against the Sea

The Battle of Saipan and the Largest Banzai Attack of World War II


By Bill Sloan

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In the midst of the largest banzai attack of the war, US Army Lt. Col. William O’Brien, grievously wounded and out of ammunition, grabbed a sabre from a fallen Japanese soldier and flailed away at a small army of assailants, screaming to his men, “Don’t give them a damn inch!” When his body was recovered the next day, thirty dead enemies were piled around him.

The Battle of Saipan lasted twenty-five hellish days in the summer of 1944, and the stakes couldn’t have been higher. If Japan lost possession of the island, all hope for victory would be lost. For the Americans, its capture would result in secure air bases for the new B-29s that would put them within striking distance of the Japanese homeland. The outcome of the war in the Pacific lay in the balance.

In this gritty, vivid narrative, award-winning author Bill Sloan fuses fresh interviews, oral and unit histories, and unpublished accounts to describe one of the war’s bloodiest and most overlooked battles of the Pacific theater. Combining grunt’s-view grit with big picture panorama (and one of the ugliest inter-service controversies of the war), Their Backs against the Sea is the definitive dramatic story of this epic battle — and an inspiring chronicle of some of the greatest acts of valor in American military history.


chapter 1

Islands of Mystery

THE ISLAND of Saipan was approximately four miles wide and fourteen miles long, giving it the second largest landmass, after Guam, in the Marianas archipelago, a group of fifteen islands that runs in a shallow, curving line for 425 miles in the mid-Pacific. Traces of human settlement found by archeologists on Saipan covered approximately four thousand years. The islands were officially discovered in 1521 by Spanish explorer Ferdinand Magellan in the course of his first voyage around the world.

Magellan was struck by the magnificent sailing power of the native boats and by the similarity of their rigging to those of the small sailing craft he had encountered in his own Mediterranean, and he labeled his discovery "Islas de las Velas Latinas" (Islands of the Lateen Sails). Some of his crewmen, however, preferred to call them the "Islands of Thieves" because of the larcenous habits of the natives, and the name remained popular well into the twentieth century.

Late in the 1600s Maria Anna of Austria, wife of Philip IV and queen of Spain, dispatched a group of missionaries and soldiers to the islands, and the official name from that time on became the Marianas Islands.

The Chamorros were the original native population of the Marianas, and as time wore on, they became agitated toward the rigid rule of the Catholic priesthood, and armed revolution broke out in the islands in the 1690s. Many of the Chamorros fled to other islands further north, where they were largely pursued and persecuted. When the US invasion of the island occurred on 15 June 1944, about 3,900 Chamorros were still living on Saipan and the neighboring island of Tinian. Many of them worked as slave laborers for the Japanese.

Imperial Germany challenged Spanish control, which had become progressively weaker during the nineteenth century. This led to the eventual 1899 cessation of all Spanish possessions in the Caroline Islands, the Marshall Islands, and the Marianas. Germany paid Spain about $4 million to acquire the islands.

In 1914, shortly after the beginning of World War I, Japan seized all but one of the islands in the chain. The League of Nations officially recognized the seizure, and in 1920 it mandated the rest of the Marianas—less Guam—to Japan with the stipulation that none of the islands would be fortified, a stipulation that Japan made a point of overlooking. Guam, the largest island in the Marianas, was owned by the United States and used as a vital coaling station and a small naval base.

IN THE YEARS between the two World Wars Saipan became known as one of Japan's "Islands of Mystery" because so little was known about what was taking place there. Japan withdrew from the League of Nations in 1935 and let it be known that she would not tolerate any challenge to her sovereignty in this part of the Pacific. She began to settle and develop the island vigorously, immigrating thousands of Japanese, Koreans, and other Asians in the process; they soon outnumbered the natives as they built sugar plantations, refineries, and other infrastructure. By 1943 approximately 33,000 civilians lived on Saipan, including the 3,900 Chamorros. The islands were very jealously guarded against visits by anyone from the West, mainly because Japan was hurrying to build a series of naval installations and airbases there. These included two airfields and a seaplane base at Saipan along with two airfields on the island of Tinian, located just three and a half nautical miles to the southwest.

By the early 1940s the Japanese regular army was composed of seventeen divisions with 464,000 men. Every Japanese division was self-sustaining with its own artillery, cavalry, engineers, tanks, and quartermaster troops, and each division contained exactly 22,000 men.

But that was only the beginning. In a crisis situation there were 738,000 members of the army reserve, all of whom had undergone the same rigorous training and could be activated at a moment's notice. This meant that the Japanese army actually totaled more than 1.2 million men. The Japanese generals had vowed to create the finest army in the world, and there were strong indications that they had done exactly that.

The typical Japanese soldier was tough and well trained to do whatever was necessary to win a battle. American reporter John Goette, who spent more than four years covering the exploits of the Japanese soldiers in China, including the killing of an estimated 200,000 civilians in the Rape of Nanking, observed, "There are no volunteers in the Japanese army, only conscripts… every Japanese male is a potential fighting unit who remains subject to call for the rest of his life. Bodily comfort, non-essential equipment, food, transport, promotion, rest and glory are purposely subordinated to achieve the high results of team play."

It was an exciting time when a Japanese boy was inducted into the army. As the train carrying the boy pulled away to conscript training, friends and family waved flags and shouted, "Banzai! Banzai!"—the traditional Japanese war cry that literally meant "[May you live] ten thousand years." The flamboyant departure let the boy know that in his people's eyes he was already considered a hero and a representative of the emperor and his country.

EVEN AS THE Japanese were fortifying the island, Saipan was also being developed as a rich agricultural center, especially for sugar. Cane fields covered hundreds of acres in lower-lying areas of Saipan, and narrow-gauge railroads were built to carry the syrup to a long pier for loading directly onto Japanese cargo ships. The railroad almost completely encircled the island along the coast, save for a few places on the more rugged eastern side.

Saipan's major peacetime industry was sugar production, with the crops from large plantations and a giant sugar mill turning out huge quantities of alcohol for producing synthetic Scotch whisky, port wine, saki, and beer. These products would come in handy for Japanese troops in the days to come. Widespread usage of alcohol would become a common tool for motivating Japanese soldiers when World War II broke out.

BECAUSE OF ITS strategic location in the Marianas, Saipan served as a major stepping stone connecting the Japanese Empire to its Pacific island fortresses. The Japanese understood the importance of the Marianas in defending their homeland and recognized that an American invasion could result in a struggle that would decide the war's outcome.

Saipan was located 1,260 miles from Tokyo. That put it out of reach from the newest US land-based bombers in the early 1940s, but when the United States developed the huge B-29 Superfortress in the mid-1940s, the entire context changed. Suddenly Tokyo and the rest of Japan would be within striking distance if US forces could secure Saipan.

Saipan was the most heavily fortified island in the Marianas. If the United States could capture it, it would have secure airbases for its B-29s. Saipan's Aslito Airfield, with a 3,600-foot runway located near the south end of the island, and another airfield, Marpi Point, under construction at the extreme north end of the island, made it even more attractive. The airfields on Tinian, slightly smaller and just three and a half miles south of Saipan, also had promise, but US forces were less familiar with them.

American proponents such as Admiral Ernest J. King, commander-in-chief of the US Fleet, advocated for capturing the island to provide a base of operations from which protected lines of Japanese communication could be severed and from which long-range aircraft could be used to bomb Tokyo and the Japanese home islands. Not everyone shared Admiral King's conviction, however. General Douglas MacArthur opposed invading the Marianas because it would be "time consuming and expensive"; he argued that an approach along the northern coast of New Guinea "offered much better chances for success."

King held his ground against MacArthur and others, however, and Saipan was chosen.

SAIPAN WOULD NOT be an easy target for an invasion at any time, but even more so in the month of June. Although the Japanese used it extensively as a rest area and training center, the island lacked the natural facilities of a major naval base. A treacherous coral barrier reef fringed much of the island, with a submerged arm curving out from the upper west coast to enclose Tanapag Harbor. Invading troops would be forced to go in over a reef seven hundred yards across in some places. Still, it was the only possible landing site, as steep hills characterized the other side of the island.

Rainfall totaled about 125 inches per year, with an average of 275 rainy days annually—and June and July were far and away the wettest months. Although the temperature ordinarily hovered between 76 and 80 degrees, June was a bad month for heat waves. The high temperatures sometimes topped out at around 95 degrees.

Almost in the center of Saipan the huge bulk of Mount Tapotchau humped its back against the sky, rising to a height of 1,554 feet, and its steep, almost perpendicular sides made it seem even higher. This mountain was a key terrain feature that gave the Japanese an excellent place to observe—and shell—the US beachhead.

THE US PLAN of attack was straightforward. The lower western coast of Saipan was divided into eight landing beaches that stretched for six thousand yards. Each beach was code-named Red Beach 1, Red Beach 2, Red Beach 3, and so on for the remaining eight areas designated by Green, Blue, and Yellow. The 2nd Marine Division would land on the northern Red and Green beaches. The 4th Marine Division would land on the Blue and Yellow beaches. Landing sites on the eastern sides of the island had been weighed and ruled out because of a variety of problems, including the rough and rocky cliffs that would give the Americans a mass of trouble in the days to come.

The west coast was the only place that would allow the two divisions to land side by side. The attack plan called for the 2nd Marine Division to anchor itself on the coast and turn left (north), while the 4th Marines would turn eastward and then north. Then both divisions would sweep to the northern end of the island, destroying the defending Japanese in their path.

In charge of the US ground troops in the invasion was Marine Lieutenant General Holland M. Smith. To many outward appearances Smith was a perfect choice to lead an amphibious landing on Saipan. He had been instrumental in making the LCVP (landing craft, vehicles, personnel) adopted by the Navy to land troops and materials on an invasion beachhead. But Smith's devotion to Marine tactics also made him an unfortunate choice to head up the Saipan assault. He considered the Army and the Navy deeply resistant to cutting-edge battle tactics, and he lost no time in saying so. Holland Smith's animosity earned him the nickname "Howlin' Mad" Smith.

The "floating reserve," consisting of the Army's 27th Infantry Division, which could be committed to battle whenever needed, was headed by Army Major General Ralph Smith (unrelated to "Howlin' Mad"). Ralph Smith was a highly decorated officer who spoke French and specialized in military intelligence and tactics. He also had, said one of his contemporaries, "extreme consideration for all other mortals."

These two general officers were destined to clash during one of the bloodiest battles in history. At the time few realized that a disagreement between two American generals would become one of the most controversial stories to come out of that struggle.

On 15 June 1944, US military forces launched the Battle of Saipan in a place totally unknown to most Americans. The invasion represented the first attempted breakthrough in an inner line of islands the Japanese had built over the past twenty-five years to protect their far-reaching—and ill-gotten—Pacific empire. When the battle ended on 9 July, Saipan would go down in history as one of the key operations of the Pacific war, one that unlocked America's air power and opened the way for US aerial attacks on the home islands of Japan.

The US military had planned that the entire process of taking Saipan would take three days. It would be among the longest three days any fighting man who was there could remember.

chapter 2

The Infernal Beach

FOR FULLY two and a half years after the Japanese attack on Pearl Harbor, the war between Japan and the United States remained far away from the shores of Saipan and her sister islands in the Marianas, except for Japan's quick and easy takeover of Guam. During this time the Marianas served the Japanese primarily as the supply and staging bases for troops, ships, and planes in battles fought far to the east and south. In May 1943, just over a year before the US attack, the Japanese had slightly more than nine hundred military troops stationed on the island—not nearly enough to repel any type of incursion.

Admiral Marc A. Mitscher and his Task Force 58, after administering a two-day shellacking of Truk in February 1944, turned toward the Marianas and gave Saipan its first baptism of fire. Suddenly what had always been considered a rear area of the war had now become front and center. And Japan got cracking—or tried to. But so did the US submarines.

On the afternoon of 29 February a Japanese transport, the Sakito Maru, was torpedoed and sunk with 3,080 troops aboard. Only 1,688 were rescued, but according to Japanese reports, all their weapons were lost except for seven rifles, one grenade thrower, two light machine guns, and 150 bayonets. American submarines played havoc with Japanese shipping for the next three months.

The last major Japanese troop movement to Saipan was the transfer of the 43rd Division, and the first shipment of troops managed to avoid the US submarines. It arrived only a few weeks before the American invasion and would play a leading role in defending the island. Its commander, Lieutenant General Yoshitsugu Saito, would assume control of the Saipan defenses. But a second shipment set sail on 30 May when a convoy of seven transports carrying more than seven thousand troops of the 43rd Division headed south. It was subjected to almost constant submarine attack, and within three days five of the seven transports were lost.

A group of three US attack submarines, known as "Blair's Blasters"—the USS Shark, Pilotfish, and Pintado—commanded by Captain Leon Nelson Blair, was instrumental in all five of these sinkings, losses that undermined Japan's ability to defend the island.

About 80 percent of the troops from the convoy were saved, but when the survivors landed on Saipan, they arrived without weapons or equipment. Altogether, from January to early June 1944, the Japanese dispatched about 45,000 Army troops to the Marianas. Of these, 40,000 were designated for Saipan, though only about 30,000 reached their destination. Although many of the survivors were reorganized and re-equipped, many others—up to 5,000 soldiers—became stragglers on Saipan, armed only with their resolution to die for their emperor.

All told, US submarines accounted for the loss of more than mere manpower. In many cases, essential building materials went to the bottom of the ocean along with the men. Captain Blair's wolf pack alone completed twenty-two successful war patrols in enemy waters, sinking thirty-four enemy ships, including two 4,700-ton freighters. Blair sent ships transporting 7,200 Japanese soldiers—and twenty-two tanks—to a watery grave.

A report from the chief of staff of Japan's 31st Army—equivalent to a US Army Corps, with 25,000 to 50,000 men—gave a clear picture of the difficulties they faced in their efforts to construct adequate fortifications on Saipan. "We cannot strengthen the fortifications appreciably now unless we get material suitable for permanent construction," read the report. "Specifically, unless the units are supplied with cement, steel reinforcements for cement, barbed wire, lumber, etc., which cannot be obtained in these islands, no matter how many soldiers there are, they can do nothing in regard to fortifications but sit around with their arms folded, and the situation is unbearable."

Captain Blair was awarded the Navy Cross and a presidential Legion of Merit for his contributions to the Saipan campaign—even before it officially started. For his conduct as commander of Submarine Division 44, he was later promoted to rear admiral.

AN ENEMY DOCUMENT published on 20 May 1944—less than a month before the US landings—called for "the immediate construction of defensive positions that when they are fully developed, they can destroy the enemy landing force on the beach. We will transform these islands into a fortress so that we can expect, absolutely, to hold our airfields."

No mention was made of constructing permanent defensive positions inland. The entire Japanese scheme of defense was committed to destroying the enemy landing force "on the beach." Through counterattacks, launched during the night from specified points, the Japanese hoped to demolish the American landing units at the water's edge—if not before.

The conclusion was inescapable: despite all their efforts, the Japanese were not fully prepared for the American landings on Saipan when they came. If they had had several more months, it might have been a different story. The Japanese found it physically impossible with the means at hand to build their defenses to a point where they might successfully resist a landing by US forces. But prepared or not, the Japanese forces on Saipan were neither weak nor feeble—far from it.

Despite the shortcomings of the defensive installations, one vital characteristic of a good defensive plan was present: the individual Japanese soldier was determined to hold the island at any cost and to give his life to realize this end. It was this characteristic that would present the greatest challenge to American forces throughout the struggle for Saipan.

IN THE BREAKING dawn of 14 June—the morning before the US landings—Rear Admiral Jesse B. Oldendorf arrived off the coast of Saipan with two bombardment groups. His force included seven old battleships, eleven cruisers, twenty-six destroyers, and a small number of destroyer transports and minesweepers. Four of the old "tin cans," the USS Tennessee, Pennsylvania, California, and Maryland, were survivors of the attack on Pearl Harbor two and a half years earlier.

The bombardment was especially effective against prepared gun positions used by antiaircraft units. A Japanese naval officer noted in his diary that "practically all our antiaircraft guns and machine gun positions were destroyed." Otherwise, the American preliminary bombardment was far less than perfect, leaving intact observation posts and gun emplacements protected by splinter-proof shelters that were capable of withstanding the shelling.

On the night of 14 June most of the support ships retired, with only a handful remaining to continue harassing fire along the coastline. In the early hours of 15 June, the Western Landing Group, consisting mostly of transports and LSTs (landing ship, tank) carrying the 2nd and 4th Marine Divisions was slowly approaching the island from the east.

AS THE LANDING crafts moved toward shore, US carrier planes came in at treetop level to make one last assault, and the shell casings from their machine guns fell red-hot into many of the boats. Some of the troops thought they were under attack by their own planes.

The Amtracks were loaded with Marine troops. And they were the first to come under attack.

Private First Class Carl Matthews heard the sound of an incoming shell, and suddenly one of the Amtracks to his left received a direct hit and vanished into a cloud of flaming smoke. He realized that the shells were coming closer and closer, and at that moment he averted his eyes and quit looking. Instead, he started some serious praying.

He closed his eyes and thought about his home and family back in Hubbard, Texas. He thought of his mother and father and his two little sisters. They seemed so far away—almost like they were in another world.

Matthews looked at Lieutenant James Stanley Leary Jr., the leader of Matthews's 2nd Platoon of C Company, 2nd Marines. He had the most serious expression on his face that Matthews could ever remember seeing. He was probably thinking about home, Matthews thought, and realizing that some of the men in his command would likely be dead a few minutes from now.

When the Marines reached the three-hundred-yard mark from shore, the Japanese shells were coming thick and fast, just as the Japanese had planned. Every twenty-five yards or so, about once every fifteen seconds, another shell would burst. Marines who had been at Tarawa or Kwajalein knew what to expect, but the greenest troops—those with no combat experience—smoked or kept their heads down and prayed. Some of them vomited as the Amtracks heaved up and down in the choppy sea.

The Marines hit the beaches at 0843. In the landing the 6th and 8th Marine Regiments got hopelessly mixed up, and the troops ended up concentrated on Red Beach 2, Red Beach 3, and Green Beach 1, which gave the Japanese a huge target to shoot at, and the casualties in these first few minutes were tremendous. Further down the beach the 4th Marines landed in a more orderly manner.

They were supposed to advance and take Afetna Point, a small protuberance jutting into the sea, and the town of Charan Kanoa and the ridge above it. But intensive Japanese shelling caused the attack to bog down, and some of the Marines were trapped on the beaches under withering fire.

Marshall E. Harris of the 2nd Armored Amphibious Battalion was crawling slowly through the water in his tank toward Green Beach 1 and talking to a close friend, Robert Lewis, in another amphibious tank nearby when Lewis's voice was drowned out by the sudden sound of an explosion. Harris felt a hard concussion. Then there was another explosion, and he saw dark smoke and fire on the water.

"Flames boiled up out of a blackened piece of metal that I realized was Robert's tank," Harris remembered, "but my platoon commander motioned for me to keep going. I never saw Lewis again. Our armored tanks just weren't up to slugging it out with an enemy land tank because of our lack of protective armor."

The 6th Marines hit a stone wall about a hundred yards inland. The driver of Private First Class R. J. Lee's amphibious tank tried to push inland away from the beach, but a deep trench stood in its way. The driver quickly threw the tank into reverse and backed out to the water's edge. As he fired his 75-millimeter cannon, he drew an instant reply from the Japanese, and the open turret of the tank took a direct, ruinous hit.

Lee saw his platoon leader and two sergeants shot dead. He watched one of his crew take a bullet in the face and go down. Lee was reaching out to him when two bullets hit him simultaneously. "I heard my four-year-old son calling, 'Get up, Daddy, get up,' and by the grace of God—and my son—I made it back to the beach," Lee said later. "Then it was lights out for me."

The American shells and bombs had torn huge craters in the sand, and smashed and burned-out Amtracks and amphibious tanks covered the beach. Behind many of them wounded men lay in every kind of agony, awaiting evacuation.

Robert Sherrod, a correspondent for both Life and Time magazines who had been at Tarawa, scribbled in his notebook: "I fear all this smoke and noise doesn't mean many Japs killed."

LIEUTENANT COLONEL WARREN ADAMS entered the Marine Corps as a well-educated New Yorker with several degrees, including a PhD from Princeton. "They put me to training new Marines," he recalled, "but after about six classes I couldn't stand it anymore, so I went to the commandant and said I wanted to quit this teaching business and get where the action was.

"I was an officer, and the only protection I had was a .45-caliber revolver." Adams said. "It was my 'war equipment,' but when you've got a mob of people coming at you, what good is a revolver? With a revolver you got in one or two shots before you were killed, but with a machine gun, you could keep the bad guys away.

"I knew a fellow in the armory department, and I gave him a bottle of whiskey and told him I wanted a submachine gun. He gave it to me, and I used it." A couple of Adams's superior officers told him he wasn't supposed to be carrying the tommy gun, but he refused to give it up, and no one insisted.

As his boat approached the beach he realized he was scared. But then he got angry at himself for being scared—the Marines had trained him well, even in hand-to-hand combat. By the time he hit the beach he wasn't scared anymore.

Adams had fought on Kwajalein and Tarawa, but for him Saipan would be the bitterest business of the lot. He had trained with five other officers, and they had become good friends. Adams would be the only one to survive: "I was the only one with a submachine gun."

PRIVATE OLIAN THOMAS PERRY was nineteen years old when he heard that the Japanese had bombed Pearl Harbor. He lived in sparsely settled Leon County, Texas, and grew up in a household with eleven brothers and sisters. He had dropped out of school and was earning a living driving a concrete truck in Houston. On the Sunday when the Japanese attacked Pearl Harbor, he was visiting his older brother, who was working on a rock crusher at Lamesa, Texas. He didn't even know what Pearl Harbor was when he first heard the news; he thought they were talking about some woman. But everything in the world changed forever that afternoon.

The next day he drove over to Waco along with two other young men, intent on joining something, even if it was the Coast Guard. As it turned out, the Navy and Coast Guard were out to lunch. But there was an old Marine there who said, "We never close, and we'll sign you up," so the three boys did just that. He told them to be in Waco early the next morning and they'd be put on a train and sent to Dallas. That's where they would be mustered in. They spent that night in a hotel and really thought they were living it up. The next morning they shipped out for San Diego—twenty-six of them on a train—and the old Marine got kind of tough on them. He said, "You're all Marines now, and from now on, by God, I want you to act like one."


  • "Sloan expertly weaves the key events of the twenty-five-day battle with account of individual and unit heroism into a fast-moving, dramatically told epic battle."—On Point: The Journal of Army History

On Sale
Jun 27, 2017
Page Count
304 pages
Da Capo Press

Bill Sloan

About the Author

Bill Sloan is a renowned military historian and the author of more than a dozen books. His narratives of World War II’s Pacific War have been praised by readers, reviewers, and veterans alike for their accuracy and their vivid writing. A former investigative reporter and feature writer, Sloan lives in Dallas, Texas.

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