In 1970, as desired by the U.S. but after much hesitation and with some key stipulations, Japan signed the NPT; and in 1972, relieved of U.S. nuclear weapons, Okinawa reverted to Japanese rule. The Diet passed a resolution formally adopting the principles in 1971, though they were not made law. Eisaku Satō was presented with the Nobel Peace Prize in 1974, in large part for his work toward Japan's entry into the NPT. In his Nobel Lecture (on the seventh anniversary of his original statement to the Diet), Satō reiterated and discussed the Three Non-Nuclear Principles and expressed hope and confidence that future governments would adopt them as well.