Host to 31 U.S. military bases, Okinawa, Japan’s southernmost prefecture, is no stranger to the risks of bearing the burden of the U.S.-Japan alliance. In 1959, the U.S. military accidentally shot a nuclear rocket into a local harbor; six years later, it lost a hydrogen bomb in nearby seas; then in 1969, a leak of nerve agent on the island so shocked the world that President Richard Nixon was forced to renounce his nation’s first-use policy on chemical weapons.