<Ul> <Li> South African nuclear weapons: disarmed from 1989--1993 </Li> </Ul> <Li> South African nuclear weapons: disarmed from 1989--1993 </Li> <Ul> <Li> Former Soviet states that disarmed and joined the NPT as non-nuclear weapons states: </Li> </Ul> <Li> Former Soviet states that disarmed and joined the NPT as non-nuclear weapons states: </Li>

When did the superpowers first agree to destroy nuclear weapons