Nuclear Proliferation

What is Nuclear Proliferation?

Nuclear proliferation is the spread of nuclear weapons, nuclear technology, fissile material, and weapons-making information to countries that do not currently possess them. This process threatens global security by increasing the risk of nuclear conflict, terrorism, and regional instability. Since the first nuclear weapons were developed, international efforts have focused on limiting both horizontal proliferation—new states acquiring weapons—and vertical proliferation—existing nuclear powers expanding arsenals.

The Non-Proliferation Treaty

The cornerstone is the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), opened for signature in 1968 and entering into force in 1970. It defines nuclear-weapon states as those that tested a nuclear device before 1967 and commits them not to transfer weapons or technology. Non-nuclear-weapon states pledge not to acquire them, while all parties promote peaceful nuclear energy use and eventual disarmament. Nearly 190 states have joined this framework.

U.S. Role and Challenges

The United States leads nonproliferation through export controls, sanctions, and diplomacy to prevent rogue states or terrorists from gaining nuclear capabilities. Learn more about how nuclear proliferation connects to nuclear proliferation and nuclear deterrence.