Q+A - U.S. base feud hits nerve ahead of Obama visit

By Linda Sieg

TOKYO (Reuters) - A feud over plans to relocate a U.S. military base on Japan's Okinawa island as part of a broad reorganisation of U.S. troops has strained Washington's ties with Tokyo ahead of President Barack Obama's Nov. 12-13 visit.

The row coincides with deepening questions about how China's rising military and economic clout will reshape the decades-old U.S.-Japan alliance, long seen as vital to regional security.

Below are some questions and answers about the origins of the dispute and whether an alliance crisis can be avoided.

WHY CLOSE THE FUTENMA BASE AND REPLACE IT?

Residents of Okinawa, 1,600 km (1,000 miles) south of Tokyo and reluctant host to about half the 47,000 U.S. military personnel in Japan, have long resented what they see as an unfair burden in maintaining the U.S.-Japan security alliance.

The concentration of U.S. military bases on Okinawa, a major U.S. military forward logistics base in the western Pacific, is a legacy of America's occupation of the island from 1945 to 1972.

Many locals associate the bases with crime, noise, pollution and accidents, and outrage flares periodically -- most strikingly after the 1995 rape of a schoolgirl by three U.S. servicemen.