Final answer:
The U.S. military used the Navajo language as a communication code in the Pacific during World War II. Navajo code talkers created a highly secure and secret code that the Japanese couldn't understand or crack, playing a crucial role in the war effort.
Step-by-step explanation:
The Native American language used by the U.S. military during World War II for communication codes in the Pacific was the Navajo language.
The Navajo code talkers were able to create a highly secure and secret code based on their language, which the Japanese were unable to understand or crack. They played a crucial role in the war effort, participating in battles such as Guadalcanal, Iwo Jima, Peleliu, and Tarawa.
The code talkers used words in Navajo that corresponded with the first letter they were trying to communicate. For example, the word 'Japan' could be represented by saying 'jacket-apple-planet-ant-night'.