Senkaku Islands dispute
In 1969, Satō struck a deal with U.S. president Richard Nixon to repatriate Okinawa and remove its nuclear weaponry: this deal was controversial because it allowed the U.S. forces in Japan to maintain bases in Okinawa after repatriation. Okinawa was formally returned to Japan on 15 May 1972, which also included the Senkaku Islands (also known as the Diaoyu Islands in China and the subject, since 1971, of a Sino-Japanese sovereignty dispute; see Senkaku Islands dispute).