The Japanese had no Native American linguists, but they weren't fools. Suspecting that the codes might be based on Indian languages, they searched among the thousands of American prisoners taken in the Philippines until they discovered Navaho Sgt. Joe Kieyoomia (1919-1997).

Despite repeated torture, Kieyoomia insisted that he couldn't understand more than a few words of the coded transmissions. Had he cooperated, Japanese codebreakers might eventually have recognized that probably "turtle" meant tank, etc., etc.

Another unsung hero.