In the first forty-eight hours of the battle of Iwo Jima, in February 1945, six Marine radio networks worked around the clock and passed more than eight hundred messages — fire coordinates, casualty reports, orders — without a single error. Every one of them travelled in a code the Japanese never came close to breaking, spoken by young men whose language American schools had spent decades trying to beat out of them. The 5th Marine Division's signal officer, Major Howard Connor, put it flatly: "Were it not for the Navajos, the Marines would never have taken Iwo Jima."
By early 1942 the Pacific war had a communications crisis. Japanese cryptanalysts, many of them educated in the United States and fluent in idiomatic English, were adept at cracking field codes, while machine ciphers were secure but agonisingly slow for fast-moving amphibious battle. Enter Philip Johnston, a Los Angeles civil engineer and First World War veteran with an unusual childhood: the son of a missionary, he had grown up on the Navajo reservation and was one of a tiny number of outsiders who spoke the language. He also knew his history — Choctaw soldiers had passed telephone messages for the US Army in the closing weeks of the First World War, in 1918, baffling German eavesdroppers. Early in 1942 Johnston pitched the idea to Major General Clayton Vogel, and a demonstration settled the matter: Navajo speakers translated, transmitted and decoded a three-line message in about twenty seconds, a job the cipher machines of the day needed half an hour to do.
The Marine Corps recruited a pilot group of twenty-nine Navajo men in May 1942 — remembered ever since as the "original twenty-nine". After boot camp they were set an unprecedented task at Camp Elliott, near San Diego: invent the code itself. The raw material was formidable. Navajo is tonal and grammatically intricate, it was then an unwritten language, and it was estimated at the time that only a few dozen non-Navajos on Earth could understand it — none of them Japanese.
A code within a language
The recruits' crucial decision was not to rely on the language alone. They built a code inside it, so that even a native Navajo speaker without the training would hear only nonsense. Military terms received poetic cover words: a dive-bomber was gini, the chicken hawk; a submarine was besh-lo, the iron fish; a tank was chay-da-gahi, the tortoise; America itself was ne-he-mah, "our mother". Everything else was spelled out letter by letter using an alphabet of Navajo words — wol-la-chee, ant, stood for A; shush, bear, for B; moasi, cat, for C — later expanded with alternate words for common letters to defeat frequency analysis. The vocabulary grew from roughly two hundred terms to more than four hundred by the war's end, and every word of it had to be memorised: nothing written went into the field.
The proof of unbreakability came from a cruel experiment the Japanese themselves ran. Joe Kieyoomia, a Navajo soldier — but not a code talker — had been captured at Bataan, and his captors, realising what they had, tortured him and made him listen to intercepted transmissions. He later said the messages were gibberish to him: a stream of birds, fish and unconnected words. Without the memorised key, even a native speaker was locked out — exactly as the original twenty-nine had designed it.
Some four hundred Navajo code talkers eventually served with the Marines across the Pacific — Guadalcanal, Tarawa, Saipan, Peleliu, Okinawa, Iwo Jima — prized wherever speed mattered more than paperwork. The bitter irony was lost on none of them: many had passed through government boarding schools where children were punished for speaking Navajo. The language their country had tried to erase was now carrying its most urgent secrets.
The long silence
When the war ended there were no parades for the code talkers, because officially there were no code talkers. The programme remained classified in case the code should be needed again, and it stayed secret until 1968. Men who had directed naval gunfire at Iwo Jima could tell their families nothing about what they had done. Recognition arrived in slow instalments: in 1982 President Reagan proclaimed 14 August National Code Talkers Day; in 2001 the surviving original twenty-nine were awarded the Congressional Gold Medal, with silver medals for those who followed; in 2002 Hollywood retold the story, loosely, in the film Windtalkers. Other tribes' contributions surfaced too — Comanche code talkers had landed at Utah Beach on D-Day, and the Choctaw pioneers of 1918 were finally honoured. Chester Nez, the last survivor of the original twenty-nine, died in 2014, a celebrated man for work he had once been ordered never to mention. The Navajo system is routinely described as the only spoken military code of the modern era never deciphered by an enemy. Its deepest lesson sits in the irony: the unbreakable code was built from a language its own country had tried to silence — and it answered by helping to save it.
Quiz nuggets
- Philip Johnston, a missionary's son raised on the Navajo reservation, proposed the code to the US Marines in early 1942; the first 29 recruits are known as the "original twenty-nine".
- In the code's alphabet, wol-la-chee (ant) stood for A and shush (bear) for B; a submarine was besh-lo, "iron fish", and a tank chay-da-gahi, "tortoise".
- At Iwo Jima six Navajo networks sent over 800 error-free messages in the first 48 hours, prompting Major Howard Connor's tribute.
- Joe Kieyoomia, a Navajo prisoner of war tortured by the Japanese, could not decode the transmissions — the code was unintelligible even to untrained native speakers.
- The programme stayed classified until 1968; the original twenty-nine received the Congressional Gold Medal in 2001, and Chester Nez, the last of them, died in 2014.