How the Battle of Saipan Ended the Japanese Empire

Image Credit: U.S. Military
July 13, 2019 Topic: History Region: Asia Blog Brand: The Buzz Tags: Imperial JapanAmericaWorld War IIImperial Japanese NavyU.S. Navy

How the Battle of Saipan Ended the Japanese Empire

The tide was turned.

The Leathernecks gained small footholds, but the Japanese fought back relentlessly. As evening neared, all hands prepared their night positions. At 0345 enemy tanks rushed the Company B, 1st Battalion, 2nd Marines portion of the line. Mortars and 37mm pack howitzers did little to halt their advance. Men used rocket launchers and antitank grenade launchers with armor-piercing shells to halt the enemy juggernaut. One intrepid Marine, Pfc. Herbert J. Hodges, stopped seven tanks with just seven rounds. When it was over, 24 tanks were laid to waste along with 700 Japanese riflemen. It had been the biggest tank battle of the Pacific War up to that time.

As the Marines moved northward, the 105th and 165th Infantry Regiments joined forces to overrun Aslito Airfield. By mid-morning on June 18, the airstrip was in American hands. The following day, the GIs made their way toward Nafutan Point on the island’s extreme southeastern tip. Leading the assault was the 1st Battalion, 105th Infantry commanded by Lt. Col. William J. O’Brien, a cocky little rooster of a man.

O’Brien pressed his men onward. His plan was to outflank the enemy on Ridge 300 near Nafutan Point. On June 21, the infantry commenced the attack with three tanks in support. O’Brien was everywhere during the battle. At one point, when one tank was inadvertently firing on its own men, he leaped on the vehicle and beat on the turret with his pistol. The tank finally halted, and O’Brien rectified the situation. Amazingly, the senior officer stayed perched on the tank throughout the firefight.

445 Japanese Pilots Lost; Most Were Teenagers

With the southern part of Saipan in American hands, Holland Smith was now poised to begin his major thrust to seize the entire island. His first objective was Mount Tapotchau in the center. Also, good news had arrived. Spruance’s ships had dealt the Japanese Combined Fleet a disastrous blow in the Battle of the Philippine Sea near Guam. Three enemy carriers plus numerous other ships had been sunk. Also, the Japanese had suffered horrendous casualties when 476 planes were shot out of the sky, and 445 of their pilots, although mostly inexperienced teenagers, were killed. This lopsided victory would soon be dubbed the “Great Marianas Turkey Shoot.”

Now with no hope of rescue, Saito and Nagumo braced themselves for the inevitable conclusion. However, the enemy was still determined to kill as many Americans as possible before giving their lives for the Emperor. As one young soldier wrote in his journal: “I will take out my sword and slash, slash, slash at him as long as I last.…”

Holland Smith conferred with General Ralph Smith and praised Smith’s soldiers, while also informing him of the impending assault on the mountain. Ralph Smith’s GIs were to move into position in the center of the line for a three-division attack. When “Howlin’ Mad” Smith left, Ralph Smith was elated and mentioned to another officer that the Army and Marines had “perfect teamwork.” Unfortunately, this euphoria would soon disintegrate and lead to one of the biggest controversies of the war between the two services.

Disgusted, the Marine commander pulled the 27th Division from Nafutan and ordered it to drive the Japanese off the mountain itself. In the meantime, the 2nd Marine Division inched its way to the northeast and the 4th Division headed eastward to capture Kagman Peninsula. The 27th and the 2nd had the worst going. In addition to the mountains and hills, there was a valley inundated with steep cliffs which the Japanese had laced with gun emplacements. The men who fought there soon began calling the area “Death Valley” and “Purple Heart Ridge.”

This labyrinth of caves, slit trenches, and ravines did not impress “Terrible Tommy” Watson, however. The 2nd Marine Division commander screamed during one firefight: “There’s not a goddamn thing up on that hill but some Japs with machine guns and mortars. Now get the hell up there and get them!”

An Unprecedented Relief of Command

On June 23, the Leatherneck divisions proceeded to attack the enemy fortifications. As 18 batteries of artillery sprung into action, Turner’s ships offshore joined in the shelling to soften the Japanese bulwarks. The 27th Division failed to link up with the rest of the assault troops because one of its regiments got lost on its way to the front.

For two days the Americans struck the enemy positions. The Marines had gained ground, but the GIs had troublesome terrain in the center. Because of this, the attacking units now resembled a large “U” with the Leathernecks’ flanks dangerously exposed.

“Howlin’ Mad” Smith had had enough. He discussed the problem with Admirals Turner and Spruance and told them he wanted to relieve General Ralph Smith of command. This was unheard of—a Marine general was relieving an Army general. Both admirals acquiesced to Smith’s decision. Ralph Smith was replaced with Maj. Gen. Sanderford Jarman. On June 28, Maj. Gen. George W. Griner arrived from Hawaii to take permanent charge of the division.

Repercussions from Holland Smith’s decision reached all the way back to Washington, DC; however, the irascible general refused to yield. “I don’t care what they do to me,” he confessed. “I’ll be 63 years old next April and I’ll retire anytime after that.”

Some historians have argued that the Marine officer was not justified in removing Ralph Smith from command. The 27th Division on Saipan had extremely difficult ground to cover. Certainly the GIs had fought as bravely as the Marines had on the island. However, someone had to be accountable, and Ralph Smith was the unfortunate one. As the “battle of the Smiths” went on, the attack on Saipan continued. And more men—Marines as well as soldiers—would die capturing the island.

Artillery Shells Deafen the Marines & Fling Them Skyward

On the evening of June 26, the enemy attempted a futile Banzai attack in the southern sector. A large group of about 500 made its way through the Army lines and struck the airstrip. The enterprising Japanese destroyed one P-47 fighter and damaged several others. Rear echelon units soon surrounded the Japanese, some hidden in caves, and finished them off. Not wanting to surrender, the survivors committed hara kiri, ritual suicide. With that, all organized fighting in the southern region was over.

All attention was now to the north. At a place dubbed “Obie’s Ridge,” the 105th Infantry surprised the enemy. Led by the feisty Colonel O’Brien, the soldiers confiscated a 75mm howitzer and five Nambu machine guns.

Meanwhile, on July 2, the 2nd and 6th Marines swept over Sugar Loaf Hill, a stone mountain that had been hollowed into a fortress. As the Leathernecks assaulted this enclave, they encountered heavy mortar and automatic weapon fire. Grenades were hurled into cave openings. Artillery shells literally picked men up and flung them back to the ground, shattering eardrums in the process.

Utilizing flamethrowers, satchel charges, and hand grenades the riflemen seized the hill. As they overran their objective, the 3rd Battalion, 6th Marines linked up with the 2nd Battalion, 2nd Marines at Garapan and Tanapag Harbor on the coast. As the weary Leathernecks cooled themselves off in the refreshing seawater, one Marine suddenly cried out: “Son of a bitch! Tomorrow is the 4th of July!”

“No Matter What Else Happens, Keep Going”

As the 2nd Marine Division was enjoying a well-deserved rest, the 4th Marine Division was moving on Marpi Point. In addition, the 27th Infantry Division pushed northward to eliminate the remainder of the Japanese defenders. The 2nd Battalion, 105th Infantry, which had been at Nafutan Point, was released and hooked up with the rest of the regiment. O’Brien continued to advance. “Keep going,” he shouted. “No matter what else happens, keep going.”

As the sun set on July 6, the 1st Battalion, 105th Infantry dug in for the night on the east side of a railroad track. The 2nd Battalion had encamped on the west side. O’Brien saw that a large opening had developed in the lines and quickly asked for additional troops to plug the breach in the perimeter. When none were forthcoming, he had all his antitank guns and heavy automatic weapons cover the area in the event of a Japanese Banzai assault. The enemy would not disappoint him.

Realizing the end was near, Saito issued his last command to his men. It read in part: “We must utilize this opportunity to exalt true Japanese manhood. I will advance with those who remain to deliver still another blow to the American Devils, and leave my bones on Saipan as a bulwark of the Pacific.… Here I pray with you for the eternal life of the Emperor and the welfare of our country, and I advance to seek the enemy. Follow me!”

Defeat and Seppuku

However, Saito was so frail he never accompanied his soldiers on their last major assault. Instead, he and Nagumo walked to another cave with two staff officers. After they bowed to each other, and in the direction of their homeland and the Emperor, they both sat down. As they plunged their samurai swords into their abdomens, the two aides put a bullet in each of their heads.