THE CODE THAT COULDN'T BE BROKEN: During World War II, a group of young Navajo men created an unbreakable code that helped the U.S. defeat Japan and win the war in the Pacific.

• Author: Brown, Bryan
• Position: TIMES PAST

For 12 years, Sam Sandoval was forbidden to speak his own language. Like many generations of Navajos, he was sent away from his home in New Mexico to a boarding school as a child. There, he was forced to abandon much of his native culture and speak only in English. Sandoval and his friends "used to sneak away and talk Navajo," he says.

Then, on Dec. 7, 1941, Japanese planes attacked the U.S. naval base at Pearl Harbor, Hawaii. The assault killed more than 2,400 Americans and plunged the U.S. into World War II (1939-45) against Japan and its allies. Like millions of other Americans after Pearl Harbor, Sandoval signed up to defend his country, enlisting in the Marines at age 19.

But he wouldn't be an ordinary recruit. To his surprise, the Marines chose him for an experiment: to help devise and use a secret code based on the Navajo language. Sandoval would become part of a legendary group of some 400 Navajos known as the code talkers. Their unbroken code helped turn the tide in key battles in the Pacific Ocean (see map) and win the war against Japan.

A Complex Language

The U.S. was at a huge disadvantage when it entered World War II in December 1941. The Pearl Harbor attack had crippled the Navy's fleet in the Pacific Ocean. By the spring of 1942, the powerful Japanese military controlled much of the Pacific, threatening Australia, an American ally, and drawing ever closer to the U.S. itself.

For the U.S. and its allies, winning the war in the Pacific would be a massive operation. Communication was among the biggest challenges. Relaying battle plans and controlling troop movements over thousands of miles of ocean required servicemen to talk by radio--and in code so that the enemy couldn't understand. But the Japanese were highly skilled at deciphering codes. It seemed that they could anticipate the Americans' every move.

In Los Angeles, California, a man named Philip Johnston thought of a solution. The son of Christian missionaries who worked with the Navajo, Johnston had grown up on the tribe's reservation, a huge 27,000-square-mile area in New Mexico, Arizona, and Utah. He knew the Navajo language was very complex. Because there was no widely used written version, almost no non-natives could understand it. Johnston contacted Marine officers with the idea of developing a code based on Navajo.

To most Navajos, that idea would have seemed highly ironic. For years beginning in the 1860s, the U.S. government had forced Navajo children to attend boarding schools designed to replace their native ways--and language--with more "American" ones. Even after they didn't have to, many Navajo parents sent their kids to those schools because they were better than the ones on the reservation.

Devising the Code

Now Navajos were being asked to use their once-forbidden language to help protect the U.S. In early 1942, the Marines started a project at Camp Pendleton near San Diego, California, with 29 young men. The Navajos were first given 211 common terms used in battle. For each, they devised a code word with a unique Navajo spin (see "Code of Battle," p. 20). For example, they called fighter planes, which were smaller and lighter than bombers, hummingbirds.

On top of this, the coders expanded their word list by spelling out English words and place names with a code based on Navajo words. For example, they would replace the English letter A with the Navajo for ant: wol-la-chee. In total, their vocabulary would include more than 800 terms.

The Navajos memorized the entire list, allowing them to be incredibly fast at transmitting messages. In field tests, they could send a four-line message in 20 seconds. (A standard coding machine took 30 minutes.) Best of all, no one other than the code talkers--not even other Navajos--could understand the messages.

Military officials were impressed. But would the code work on the battlefield?

A Trial by Fire

They soon found out. In July 1942, the Japanese invaded Guadalcanal in the Solomon Islands, giving them an air base even closer to Australia. Alarmed, U.S. military officials organized a hurried invasion of the island. On August 7, the first wave of Marines stormed the beach in what would be a six-month ordeal. In November, the code talkers joined them.

The fighting was brutal. Marines trudged through thick jungle, facing death at every step. Because of the jungle tree line, U.S. planes couldn't see where to bomb Japanese positions or drop supplies. The code talkers and their radios were often the only lifeline the Marines had to medicine, ammunition, food, and one another.

Chester Nez, one of the original 29 code talkers, later wrote about working nonstop for 24 hours at a time, crammed into a foxhole. He described his first radio transmission, calling in an attack on a Japanese machine gun that had his patrol pinned down.

"A runner approached, handing me a message written in English. [I transmitted the message to another code talker:] 'Enemy machine gun nest on your right. Destroy.' Suddenly, just after my message was received, the Japanese gun exploded, destroyed by U.S. artillery."

Taking Iwo Jima

Working so quickly with a code the enemy couldn't...