The Northern Mariana Islands had become a Japanese protectorate before the war. It was the Chamorros from the Northern Marianas who were brought to Guam to serve as interpreters and in other capacities for the occupying Japanese force. The Guamanian Chamorros were treated as an occupied enemy by the Japanese military. After the war, this would cause resentment between the Guamanian Chamorros and the Chamorros of the Northern Marianas. Guam's Chamorros believed their northern brethren should have been compassionate towards them, whereas having been occupied for over 30 years, the Northern Mariana Chamorros were loyal to Japan.