What ultimately won the Battle of Saipan wasn’t a weapon. It was understanding.
June 15, 1944: The Battle of Saipan began.
The United States brought overwhelming firepower to the island. Battleships shelled the coast. Aircraft bombed defensive positions. Tens of thousands of Marines and soldiers landed on the beaches.
American planners quickly discovered that the battle would be far more difficult than anticipated. Japanese troop strength on Saipan was roughly double what intelligence officers had estimated before the invasion.
Saipan’s rugged terrain contained hundreds of caves, tunnels, and concealed positions. As American forces advanced, thousands of Japanese soldiers and civilians retreated into these underground strongholds.
The caves created a new battlefield. Soldiers could not simply see the people they were fighting. Many civilians were trapped alongside military personnel. Rumors, fear, and misinformation spread easily in the darkness.
Courtesy of U.S. National Archive and Records Administration
The invasion of Saipan began with overwhelming firepower. But victory would require far more than ships, planes, and artillery.
Courtesy of U.S. Department of Defense
U.S. Marines came ashore under heavy fire during the opening days of the Battle of Saipan. The fighting would become some of the fiercest of the Pacific War.
Courtesy of U.S. National Archive and Records Administration
American commanders expected a difficult battle on Saipan. What they found was an island defended by far more Japanese troops than intelligence had predicted.
Before they entered caves or interrogated prisoners, MIS soldiers spent months studying Japanese language, military terminology, and intelligence techniques.
Understanding the Misunderstood
Many American commanders understood how to fight the Japanese. Few understood how Japanese soldiers and civilians thought.
That difference mattered.
As the battle unfolded, Military Intelligence Service (MIS) soldiers found themselves performing some of the most important work on the island. Their job was not simply translating Japanese words into English. They understood the language, culture, customs, and values of the people they were trying to reach.
That understanding saved lives. Early in the campaign, American intelligence officers prepared propaganda leaflets encouraging Japanese soldiers and civilians to surrender. The language sounded reasonable to Americans. To many Japanese readers, however, the wording was insulting.
Unsung Heroes
T/3 Harold Nishimura immediately recognized the problem. The leaflets failed to account for Japanese ideas of honor and obligation. The leaflets were revised.
Team Chief Sergeant Tim Ohta received the Silver Star for negotiating with Japanese soldiers while under enemy fire.
Sgt. Jack Tanimoto also received the Silver Star after helping civilians escape while holding off Japanese soldiers with his rifle.
Even those who were not Japanese American played important roles. Pfc. Guy Gabaldon, a Mexican American who had grown up in a Japanese American family in Los Angeles, used his understanding of Japanese language and culture to persuade hundreds of soldiers and civilians to surrender. He became known as the “The Pied Piper of Saipan.”
Courtesy of Tanimoto family
Sgt. Jack Tanimoto received the Silver Star for helping Japanese civilians escape danger while holding off enemy soldiers under fire.
U.S. Marine Corp Photo
Raised by a Japanese American family in Los Angeles, Pfc. Guy Gabaldon used his knowledge of Japanese culture to persuade hundreds of soldiers and civilians to surrender.
Courtesy of U.S. National Archive and Records Administration
Convincing Japanese soldiers to surrender often required trusted voices. Former holdouts became powerful advocates for laying down arms.
Courtesy of U.S. National Archive and Records Administration
Sgt. Bob Hōichi Kubo comforts a frightened Japanese child on Saipan. His ability to communicate across cultural and linguistic barriers helped save lives during the battle.
Sgt. Bob Hōichi Kubo of Hawaiʻi became the only MIS soldier to receive the Distinguished Service Cross during World War II for his actions on Saipan.
The Highest Honor
Perhaps no story better illustrates the value of understanding than that of T/4 Hōichi Kubo.
During the battle, Kubo learned of Japanese plans for gyokusai, or mass suicide attacks. The information gave American forces valuable time to prepare.
Later, Kubo approached Japanese soldiers hiding in a cave. Instead of threatening them, he offered K-rations and spoke with them about duty, honor, and the realities of the war.
It became a conversation between people who understood one another. The Japanese soldiers surrendered and the civilians emerged safely.
For his actions, Kubo received the Distinguished Service Cross, becoming the only MIS soldier to receive the award during WWII.
Key to Victory
The battle was fought not only with rifles and artillery, but also with information.
MIS teams recovered approximately fifty tons of captured Japanese documents on Saipan. The material provided crucial intelligence about Japanese military operations and helped American planners throughout the remainder of the Pacific War.
The Battle of Saipan was a major American victory.
In the caves of Saipan, words often accomplished what bullets could not. Civilians emerged from hiding. Soldiers surrendered. Critical intelligence was recovered.
Many Nisei soldiers risked their lives to save others, knowing they could be shot by either side. Their greatest contribution was the ability to bridge two worlds at war.
Marine Corps Archives & Special Collections
Saipan’s caves held more than soldiers and supplies. They also contained a vast collection of Japanese military documents that MIS soldiers translated into actionable intelligence.
Courtesy of U.S. National Archive and Records Administration
Japanese civilians sheltered in caves across Saipan as the battle raged around them. Many feared capture more than death after years of wartime propaganda.
Signal Corps Archive
Not every story on Saipan ended in death. Thousands of Japanese civilians eventually emerged from the island’s caves and battlefields, choosing survival over despair.