Guadalcanal, Tarawa, Peleliu, Iwo Jima... the Navajo code talkers took part in every assault the U.S. Marines conducted in the Pacific from 1942 to 1945. They transmitted messages by telephone and radio in their native language -- a code that the Japanese never broke.  The idea to use Navajo for secure communications came from Philip Johnston, the son of a missionary to the Navajos and one of the few non-Navajos who spoke their language fluently. Johnston, reared on the Navajo reservation, was a World WWI veteran who knew of the military's search for a code that would withstand all attempts to decipher it. The "Code Talkers" could encode,  transmit, and decode a three-line English message in 20 seconds. Machines of the time required 30 minutes to perform the same job with no degree of security. A highlight of the tour was attending the Reunion of Honor Ceremony at Iwo Jima.