"As the U.S. and Japanese governments in recent years have steadily strengthened key elements of the U.S.-Japan alliance, they continue to struggle with how to manage the large-scale presence of U.S. troops in the southernmost Japanese prefecture of Okinawa. With the legacy of the U.S. occupation of Japan following World War II and Okinawa's key strategic location, Okinawa hosts a large share of the more than 50,000 U.S. military personnel stationed in Japan. About 25% of all facilities used by U.S. Forces Japan (USFJ) and over half of USFJ military personnel are located in the prefecture, which comprises less than 1% of Japan's total land area."
CRS In Focus, IF10672
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html