The Limited Test Ban Treaty was an arms control agreement negotiated by the US, USSR, and UK in 1963 prohibiting tests of nuclear devices in the atmosphere, in outer space, and underwater. It did not prohibit underground nuclear testing, so long as radioactive debris was contained within the “territorial limits” of the testing state. The treaty has since been signed by a total of 116 countries, including potential nuclear states Argentina, Brazil, India, Israel, Pakistan, and South Africa. Though two major nuclear powers, France and the People’s Republic of China, have not signed, they are now abiding by its provisions. In 1992, China exploded a bomb beyond the LTBT limits.