Local opposition to the U.S. bases over noise, safety and crime flared into mass protests after the 1995 rape of a schoolgirl by three American servicemen. The outcry eventually led to an agreement to close a major Marine airfield, but the plan has stalled for more than a decade over where a replacement facility should be located.
More than half of all U.S. troops in Japan are stationed on Okinawa, and the recent incidents have further inflamed tensions and distrust.
About 1,300 people held a protest earlier this week over the alleged October rape and the deployment of the Marine Corps' MV-22 Osprey to a base there. Many Okinawans believe the aircraft isn't safe to operate over their crowded cities.