Battle for Saipan, Part One
By David H. Lippman
February 2014

“Off for ‘Forager,’” wrote Lt. Bartlett Stoodley of the battleship USS Washington in his diary, on June 8, 1944. “Task Force 58 fills the ocean with ships! In the van we are steaming under quiet skies, bringing to the Marianas the greatest storm of shells and bombs that has ever been concentrated in the Pacific. We are wondering also what forces the Japs have concentrated to repel this threat.”

After Saipan's conquest, American B29 bombers prepare to pound Japan.

In the high summer of 1944, the United States was coiling a massive fist in the Central Pacific, aimed directly at the Mariana Islands, specifically Saipan, Tinian, and Guam. By taking Saipan and Tinian (and liberating Guam, American territory snatched by the Japanese just after Pearl Harbor), the Americans could turn these islands into airbases for their B-29 Superfortress bombers, which could in turn pound Japan’s factories and cities into rubble.

Saipan was the major target. Part of the German Empire until World War I, it had been captured by the Japanese in 1914, and awarded to them at the Treaty of Versailles under a League of Nations mandate. The Japanese had focused more economic development on the island in two decades than its previous German and Spanish masters had in three centuries. The Japanese South Sea Development Company took over the German sugar plantations, and imported Japanese citizens and Korean laborers to work them – so much so that the Japanese colonists now outnumbered the native islanders.

To seize this island chain from the Japanese, the Americans assigned the US 5th Fleet, under Vice Adm. Raymond A. Spruance, centered around 15 aircraft carriers and 10 fast battleships, 535 combatant ships and auxiliaries in all. The assault force would consist of 130,000 Marines and Army troops, organized into the III Amphibious Corps and the V Amphibious Corps. The latter formation, under Marine Lt. Gen. Holland M. “Howlin’ Mad” Smith, was tasked with invading Saipan. It consisted of the 2nd Marine Division and the 4th Marine Division. Its floating reserve was the Army’s 27th Infantry Division, drawn from the New York State National Guard.

 “Operation Forager,” as the descent on the Marianas was called, was a massive assault: Saipan was 3,500 miles from Pearl Harbor, and troops were embarked from Hawaii and the West Coast. A seaborne logistical framework of enormous proportions would be needed to keep the invading ships and men supplied with shells, bullets, and food. D-Day was set for June 15.

The Japanese defense of Saipan was headed by the newly-organized 31st Army, under Lt. Gen. Hideyoshi Obata, which was also responsible for the Caroline and Palau islands. To hold these islands, Tokyo began pulling troops from the Manchurian border with the Soviet Union, augmenting them with drafts of newly-enlisted teenagers and conscripted high school or college students. In February 1944, the Japanese sent the transport Sakito Maru to the Marianas, loaded with 4,100 infantrymen, a tank regiment, and dozens of heavy guns. As the transport approached the Marianas, the American submarine Trout fired a spread of torpedoes at the ship, sending it to the bottom on February 29, along with its tanks and guns. Only 1,700 men survived the sinking.

The Japanese tried again on May 14, with the 118th Infantry Regiment, sending them in seven transports, and more American submarines pounced on this group, sinking four of them. The 118th lost 858 officers and men out of 3,463 in transit, along with all their weapons and ammunition.

Among the young men in the 118th’s convoy was Sgt. Takeo Yamauchi, a conscripted Russian-language student, who admired Soviet Communism. His ship wasn’t sunk, but the journey was still an ordeal. “We were laid out on shelves like broiler chickens,” he said later. “You had your pack, rifle, all your equipment with you. You crouched there, your body bent. You kept your rubber-soled work shoes on continually, so your feet got camp and sweaty. Water dripped down on you, condensation caused by human breathing. The hold stank with humanity. A few rope ladders and one narrow, hurriedly improvised stairway were the only ways out. We expected the ship to sink at any moment. We were told to put our watches into rubber bags. We had a little food to nibble for survival at sea.”

Obata now had an army of 22,702 men on Saipan, but it was an incredibly disorganized force – tankers without tanks, artillerymen without field pieces, infantrymen formed into mixed special companies. Nor was there unity of command in Saipan: the naval forces were commanded by Vice Adm. Chuichi Nagumo, and the Imperial Japanese Navy and Imperial Japanese Army had a long tradition of not getting along.

Nagumo, a dour torpedo and destroyer expert in peacetime, was also a damaged brand. He had led Japan’s elite carrier fleet to its staggering victory at Pearl Harbor, then dealt death and destruction across the Indian Ocean without suffering even scratched paint, until the Battle of Midway in June 1942. There he lost four carriers in a single day. In subsequent battles, Nagumo hadn’t done much better, showing indecisiveness and vacillation at key moments. For his failures, Nagumo had been yanked off his carrier’s flag bridge and assigned to command Saipan’s less glamorous collection of yard craft, barges, and 6,690 officers and sailors, which included 800 men of the 1st Special Naval Landing Force, Japan’s version of America’s Marines, and 400 men of the 55th Naval Guard Force.

It all added up to 43,682 Japanese defenders on the rocky, craggy island, but Obata was not one of them – when the Americans arrived, their invasion caught him returning from an inspection trip to the Palaus, and he got no closer than Guam. The land battle would be conducted by Lt. Gen. Yoshitsugu Saito, centered on his own 43rd Infantry Division. His other forces included the 47th Independent Mixed Brigade, the 7th and 16th Independent Engineer Regiments, the 3rd Independent Mountain Artillery Regiment and its two dozen 75mm guns, the 25th Anti-Aircraft Regiment, and the surviving 36 medium T-97 and 12 light tanks of the 9th Tank Regiment. Their effectiveness was difficult to assess – many of their officers had gone down with their freighters, and Saito spent a great deal of time signing field promotions which suddenly put platoon leaders in command of companies, while company commanders took over battalions, without adequate time to learn their jobs.

Saito’s plan was simple: defeat the enemy on the beaches. To do so, Saito planned immediate counterattacks to weaken the Americans. Saito’s tanks would then deliver the knockout punch. Problem was, he didn’t know where the Americans would land. So he had to defend the entire coastline. If equally deployed, he would have one company of infantryman for every mile of coast. Nevertheless, Saito divided the island into four sectors, positioning his troops to cover any contingency. Saito also deployed eight Armstrong- Whitworth 6-inch guns, nine 140-mm, eight 120-mm dual purpose guns, four 200-mm mortars, and a number of concrete blockhouses. But many basic entrenchments were not built. Most of the supplies Saito and Obata had requested from Tokyo to build emplacements and trench systems had not arrived. Other supplies had been sunk in transit. Saito complained to Nagumo that unless the Navy escorted his convoys to Saipan, his men could “do nothing but sit around with their arms folded.”

Even so, they didn’t seem to do enough – the invading Americans would find hundreds of anti-boat mines not placed, bales of barbed wire not strung, and tons of building material not used. Many emplacements and trench systems were just being dug when the Americans arrived. The truth was that the Japanese, despite three years of war, did not expect the Americans to be able to reach and invade Saipan.

Yamauchi was not impressed with Saipan’s defenses, either. “Along the coastline there were only a few partially dug trenches, ” he recalled, “like earthworms laid out on the sand. I noticed no concrete gun emplacements. I heard some noise coming from high above in the mountains, and was told that they were constructing heavy artillery positions up there.”

Still, the Japanese had some strengths – tough discipline, ferocity in battle, the reliable Arisaka rifle, and the powerful Nambu machine-gun. The Arisaka rifle had an advantage over its American counterpart, the M1 Garand: the Arisaka’s smokeless powder was truly smokeless, while the M1’s powder flashed in the dark, revealing its handler. And for once, American intelligence let down its bosses – they underestimated the number of Japanese defenders by half.

But the Americans, schooled in Japanese tenacity by bloody battles in the Solomons, New Guinea, and Tarawa, approached the invasion of Saipan with the thoroughness and technical skill that would be their hallmark throughout the Pacific campaigns. American troops went into battle well-trained and well-equipped, from ration packs to rifles. The Americans could also count on air superiority, ample naval support, easily-maintained and replaced equipment, excellent medical care, and even good food. Both the Marines and the Army relied on solid combinations of artillery, armor, and infantry in battle, with the Army’s well-proven tactic of “holding attacks” to draw off the main defenders while a second force sought an opening on the flanks to defeat the enemy. A simple tactic to teach at Fort Benning, it was the perfect method of war for the vast draftee army the Americans sent to the Pacific.

Both sides had high morale. The Japanese were filled with their distorted version of the Bushido spirit, that emphasized personal courage, and death before dishonor, while the Americans were determined to avenge the defeats of Pearl Harbor and Bataan. The American fleet sailed from various ports between late May and early June. As they steamed toward battle, the ships’ loudspeakers announced the Allied invasion of France on June 6, which was greeted by some with a roar of satisfaction. On another ship, the loudspeaker announced, “The invasion of France has started. That is all.”  Dead silence in response. Then someone said, “Thank God!”

The story continues in Part Two.

Invade Saipan in Panzer Grenadier: Saipan 1944!

A shorter version of this appeared in the February 2014 issue of WW2 History magazine, published by Sovereign Media, and is used with permission.

David H. Lippman, an award-winning journalist and graduate of the New School for Social Research, has written many magazine articles about World War II. He currently works as a public information officer for the city of Newark, N.J. We're always pleased to add his work to our Daily Content.