Which aspect made the Navajo code unique compared to other military codes?

The uniqueness of the Navajo code primarily stems from the fact that it was based on a Native American language. This aspect set it apart from other military codes, which often used simple substitution methods or relied on English words. The Navajo language, with its complex syntax and tonal qualities, was not widely known or understood by the Japanese who were the primary adversaries during World War II. This linguistic foundation allowed for the creation of a code that was both intricate and secure, since the vast majority of people had no familiarity with it.

Additionally, the use of the Navajo language involved a group of Navajo speakers who were recruited to create a system of codes that incorporated common military terms translated into their language, further enhancing its effectiveness. This strategic advantage not only contributed to successful military operations but also recognized and honored the cultural heritage of the Navajo people.

The other aspects mentioned—modern technical jargon, digitalization, and military experience—do not contribute to the distinguishing nature of the Navajo code as a communication tool during the war.