When America entered the war in 1941, a First World War veteran, Phillip Johnston, suggested that the use of Native American language be revived for codes. Johnston even staged demonstrations and showed that the Navajos could encode, transmit, and decode a three-line English message in 20 seconds. It took a military decoding machine 30 minutes to do the same task. By the end of the war, there were Code Talkers from 16 different tribes. They served around the world in the US Army, Navy, and Marines. Men recruited to be code talkers were sent to a special school where they learned how to be radio operators, how to transmit code, handle weapons, and repair radios. For everyday communication, the code talkers simply spoke to each other in their native language. The code talkers were sent to fight the Japanese in the Pacific theatre. They handled all major battlefield communications.