The American invasion of the Japanese stronghold of Saipan in the western Pacific was an incredibly brutal battle, claiming 55,000 soldiers’ and civilians’ lives in just over three weeks in the summer of 1944. The U.S. Marines spearheaded the amphibious landing, encountering a fierce and well-prepared resistance from the Japanese troops who controlled the commanding heights looming over the beach.

Artillery, snipers and automatic weapons took a deadly toll with casualties mounting under the remorseless barrage. Marines later commented on the precision of the Japanese mortars and artillery fire. A battalion caught out in the open took heavy casualties as it desperately tried to dig in and find shelter, with one of its officers recalling: “it’s hard to dig a hole when you’re lying on your stomach digging with your chin, your elbows, your knees, and your toes. … (But) it is possible to dig a hole that way, I found.” Such was a precarious beachhead established on the first day of the invasion.

The amphibious landing at Saipan drew on the lessons of previous conquests in Tarawa in November 1943 and the Kwajalein and Eniwetok atolls in the Marshall Islands in early 1944. Next up was the Mariana Islands of Guam, Saipan and Tinian, part of the island-hopping campaign adopted by the U.S. that struck deeper into the Japanese defenses, bypassing some well-fortified islands and cutting off their supply lines. Saipan was almost equidistant from the Marshall Islands and Japan, nearly 2,100 km, putting much of the archipelago within B-29 bomber range.

Unlike the flat atolls, Saipan had topography and was a relatively large 185 sq. km. It had been administered by Japan since it was taken from Germany and Tokyo was awarded a mandate by the League of Nations in 1920. Although Japan had already withdrawn from the League in 1933 due to criticism of its invasion of Manchuria, it fortified Saipan from 1934 in violation of the mandate terms, making it a formidable target. The Saipan invasion was code-named Operation Forager and involved practice landings, and training with explosives and flamethrowers for three months.

The U.S. forces confronted about 30,000 Japanese troops, double pre-invasion estimates. On June 14, some of the battleships that had been severely damaged during the attack on Pearl Harbor and since repaired, commenced the softening-up phase, pounding the Japanese defenses with their heavy guns, launching shells nearly the size of a VW Beetle. It was payback time.

The U.S. forces faced an implacable foe ready to die rather than surrender and from the outset everyone knew this would be a bloodbath. On the second night, the Japanese counterattacked with 44 tanks, losing 24 of them to the marines’ intense fusillade. In the first four days alone, the marines suffered 5,000 casualties.

On June 17, with the main Japanese fleet steaming for a showdown in the Marianas, U.S. carriers were deployed to meet them while transport and supply ships were withdrawn from their offshore support positions in Saipan. On June 19, in what military historians dub the “Great Mariana’s Turkey Shoot,” the U.S. decimated the Japanese carrier task force, sinking three carriers and shooting down 330 of the 430 planes launched and preventing relief of the Japanese forces on Saipan. The U.S. supply ships returned, but the Japanese were cut off.

The U.S. confronted a tactical nightmare of ravines, caves, cliffs and hills earning nicknames such as Hell’s Pocket, Death Valley and Purple Heart Ridge. With such favorable terrain for the dug-in defenders, the U.S. resorted to unorthodox methods. One marine observed: “The flame thrower tanks were spouting their napalm jets upward into … caves. It was quite a sight!”

Many civilians died in the battle. U.S. forces didn’t always distinguish between noncombatants and combatants when entering caves or hearing movement or voices in the jungle because Japanese troops used civilians as decoys to ambush American soldiers. The brutality of the conflict is also evident in video footage that captures the tragedy of Japanese civilians committing suicide by jumping off a cliff into the ocean.

The suicides in Saipan drew considerable attention and praise in Japan. A correspondent from the Yomiuri praised the women who committed suicide with their children by jumping from the cliff, writing that they were, “the pride of Japanese women.” He even went so far as to call it, “The finest act of the Showa period.” Similarly, Tokyo University professor Hiraizumi Kiyoshi gushed in the Asahi Shimbun, “100 or 1,000 instants of bravery emit brilliant flashes of light, an act without equal in history.”

Based on numerous wartime diaries and essays, Donald Keene highlights the conspiracy of silence about the gathering decline in Japan’s war fortunes in “So Lovely a Country Will Never Perish.”

“Not until Japan had suffered severe defeats, especially at Saipan, were voices heard warning of disaster, and even then were muted, for fear of being overheard by the feared military police,” Keene wrote.

In order to bolster morale, the government invented victories and enemy losses, a web of deceit that blinded the public and leaders to the real situation. After Saipan fell, the B-29s corrected this fallacy.

As later happened in Okinawa, Imperial troops encouraged and instigated group suicides, warning of the horrible fate that awaited anyone captured by the invaders.

The Japanese commander, Gen. Yoshitsugu Saito, reportedly said: “There is no longer any distinction between civilians and troops. It would be better for them to join in the attack with bamboo spears than be captured.”

Gen. Saito, wounded and knowing the battle was lost, committed suicide in his cave on July 6 after ordering a final banzai charge. The following day, 3,000 troops, including any wounded who could still limp or crawl their way to death, obeyed orders and mounted a final mass banzai charge. These troops were annihilated, but not before inflicting heavy casualties on the American forces. By July 9, mopping up operations were completed.

Given the horrific carnage and atrocities endured and inflicted, there is an odd ring to the chivalry claimed in the aftermath of the battle. “Several times when we tried to feed newly captured women and children first, the male would shove them aside and demand to be first for rations,” one soldier noted. “A few raps to the chest with a rifle butt soon cured them of that habit.”

Of the 71,000 U.S. troops that landed, nearly 3,000 were killed and more than 10,000 wounded. Out of the entire Japanese garrison of 30,000 troops, only 921 prisoners were captured; the rest died. The Japanese commanders, and some 5,000 others committed suicide rather than surrender.

It could have been much worse. As one survey concluded, the “unfinished state of the Japanese defenses was, in fact, a critical factor in the final American victory on Saipan. The blockading success of far-ranging submarines of the U.S. Navy had drastically reduced the supplies of cement and other construction materials destined for elaborate Saipan defenses, as well as the number of troop ships carrying Japanese reinforcements to the island.” One Japanese POW observed during an interrogation that had the American assault come three months later, the island would have been impregnable and thus the casualty rate much higher.

The subsequent Battle of Okinawa (April 1-June 22, 1945) nearly a year later demonstrated how deadly improved defenses could be for the invaders, defenders and civilians. There, as many as 200,000 Okinawan civilians died in the prolonged conflagration, perhaps one-third of the entire population, along with 77,000 Japanese and 14,000 American soldiers.