In 1966, the United States, the Soviet Union, the United Kingdom, France, and China not only were the only countries that possessed nuclear weapons; they also had enough wisdom to recognize the dangers posed by nuclear proliferation.

Despite their many and deep political differences, they arrived at a consensus to halt the further dissemination of “nuclear weapons or other nuclear explosive devices.”

Under the resulting 1970 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), non-nuclear states agreed not to pursue nuclear weapons and to accept International Atomic Energy Agency (IAEA) safeguards on all their nuclear activities. In return, the five nuclear-weapon states committed to negotiate “in good faith on effective measures relating to cessation of the nuclear arms race ... and to nuclear disarmament.”