World War II’s Unbreakable Code: How Did the Navajo Code Talkers Win the Pacific?

Imagine a code spoken in an unwritten language while fighting. This was the U.S. Marine Corps Navajo Code Talkers’ role in World War II.

Apr 10, 2024By Matt Whittaker, BA History & Asian Studies

navajo code talkers wwii unbreakable code


Employing Native Americans as ‘Code Talkers’ for encrypted battlefield conversations first occurred during the Great War. Cherokee speakers served with the U.S. Army, transmitting messages at the 2nd Battle of the Somme. Other Native American soldiers, the Comanche and Osage, served in different units. In total, nine Native American languages provided a secure communication method.


Native American languages as a code became known between the World Wars. By the 1930s, many Native American languages used or developed their own Latin alphabet. Nazi Germany even sent anthropologists to study those languages. They also used newspapers, opinion polls, or ads to discourage Native Americans from enlisting. However, the Navajo spoke a complex language, unlike other tribes. First, few outside the Navajo Nation spoke it fluently, and not having an alphabet made it a good choice for battlefield use. At best, only a handful of people spoke a smattering of Navajo.


Navajo Encryption

Navajo Nation
Navajo Nation. Source: Wikimedia Commons


The gist for using Navajo for coded conversations occurred to Philip Johnston, a civil engineer, in 1942. Johnston had grown up on the Navajo Reservation, being the son of a Christian missionary. He spoke conversational Navajo and knew its uniqueness. With that knowledge and the Great War example of code talkers, he approached the U.S. Marines Corps.


Johnston demonstrated with several Navajos how unintelligible radio conversations could be. The Marines bought in; Johnston enlisted with twenty-nine Navajos. These initial soldiers worked with a cryptologist, using word substitution. Nonexistent words in Navajo got different terms, such as submarine, which turned into “iron fish.”

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The first cipher contained 211 words, which increased to 700 by 1945. According to the U.S. Marine Corps, the Navajo Code remains modern history’s only unbroken military code. Besides the cipher, the lack of a Navajo alphabet meant no writing existed for the language to be hacked. Famous examples of World War II codes proving vulnerable are Nazi Germany’s Enigma machine by Great Britain and the U.S. Navy’s breaking the Imperial Japanese Navy code before Midway. 


The program did encounter problems. First, there were only a certain number of qualified candidates to meet demands. Navajo is not a widely spoken language, unlike Spanish. As Marines, each Navajo needed to pass basic training as any Marine recruit would, using weapons, including speaking English and Navajo. Next came radio training, which involved sending messages and using the radios. Their final training was code talking, learning the codes, and helping develop them more. 


Codes in World War II

The Navajo Code Talker Memorial in Window Rock, Arizona. Katherine Locke/NHO. Source: iStock.
The Navajo Code Talker Memorial in Window Rock, Arizona. Katherine Locke/NHO. Source: iStock.


Eventually, 400 Code Talkers served in the PTO or Pacific Theater of Operations. From the Guadalcanal landings to the deadly 1945 Okinawa fighting, Navajo radio operators facilitated the fighting, their secure communications frustrating the Imperial Army. They couldn’t make sense of the weird sounds and words being broadcasted!


The Japanese captured a Navajo soldier, Joe Kieyoomia, in 1941, conquering the Philippines. Kieyoomia served before the Code Talkers existed. The Imperial Army learned that the Code Talkers used Navajo, but no one knew how. They tortured Kieyoomia regularly, making him listen to transmissions. He recognized his language but only as babble. It remained a mystery for the duration of the war.


They Played a Key Role in Island Landings

Carl Nelson Gorman, one of the original 29 Navajo code talkers, tracks enemy movements on Saipan. 1944. Source: Rare Historical Photos
Carl Nelson Gorman, one of the original 29 Navajo code talkers, tracks enemy movements on Saipan. 1944. Source: Rare Historical Photos


Navajo Code Talkers landed on the main beaches with Marine communication units. Only one Code Talker died in fighting out of hundreds. Their commanders happily praised the Code Talkers for their speed and efficiency. They reported critical information like enemy troop movements, fire support, coordinate operations, casualties, and unit changes. Their units landed on all the major, critical campaigns, such as Guadalcanal, Tarawa, and Iwo Jima. At Iwo Jima, a Marine commander bluntly stated the Navajo’s communications skills were the primary reason the Marines won. The small island’s importance as an unsinkable airfield became critical.


Success and Legacy

2015 Code Talker
2015 Code Talker. Source: USMC


The Navajo Code Talkers triumphed, remaining an unbreakable code and happily approved by their fellow Marines. The reason is simple – being a tribal language, it was only translatable to native speakers. Transmissions were made in the clear. And this disturbed the Japanese badly. Japanese intelligence used English speakers to confuse and ambush Marines, so Navajo always remained an obstacle. Navajo Code’s other advantage was nothing needed to be developed from scratch. The Navajo Code Talkers showed the importance of tribal languages in the U.S., helping preserve their language, and using their exclusive skills to help win a war.

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By Matt WhittakerBA History & Asian StudiesMatt Whittaker is an avid history reader, fascinated by the why, how and when. With a B.A. in History and Asian Studies from University of Massachusetts, he does deep dives into medieval, Asian and military history. Matt’s other passion besides family is the long-distance Zen-like runs.