The Code the Japanese Never Broke

In the spring of nineteen forty-two, the Marine Corps recruited twenty-nine young Navajo men and gave them an unusual assignment: invent an unbreakable military code using their native language. The Navajo language, with its complex tonal system, irregular syntax, and almost no written form outside ceremonial use, was known to fewer than thirty non-Navajo speakers on Earth. The Japanese, who had cracked earlier American codes, never came close to this one.

The code worked on two levels. For common military terms the recruits created Navajo equivalents: a submarine became iron fish, a fighter plane became hummingbird, a battleship became whale. For words without Navajo equivalents they built an alphabet: the Navajo word for ant, which sounds like wol-la-chee, stood for the letter A. A message that could take thirty minutes with a mechanical cipher device took a trained code talker about twenty seconds.

By the end of the war, more than four hundred Navajo men had served as code talkers across every Marine division in the Pacific. At Iwo Jima, Major Howard Connor had six of them working around the clock during the first two days of the assault. He later said: "Were it not for the Navajos, the Marines would never have taken Iwo Jima."

The program remained classified until nineteen sixty-eight, leaving the men unable to describe their wartime service even to their families. Congress awarded the original twenty-nine code talkers the Congressional Gold Medal in two thousand one. For a generation, their contribution was the country's best-kept secret.