It’s a 50-year-old compromise that helped pull the world back from the brink of nuclear war. And today, it’s future hangs in the balance.

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT),  signed in 1968 by the United States, Russia and other major world powers, stipulated that countries with nuclear weapons would take significant steps to reduce their stockpiles, and those without arsenal wouldn’t attempt to acquire them.

The agreement was a last ditch effort to stem the spread of nuclear weapons technology and reduce the risk of catastrophic nuclear war, particularly between the U.S. and the Soviet Union.

As our latest Above the Noise video points out, the treaty  didn’t stop nuclear proliferation altogether, but it did help dramatically slow the nuclear arms race of the Cold War. As a result, 16 nations agreed to abandon their budding nuclear programs. Nearly every nation in the world has now signed on to it (with a handful of notable exceptions). And while Russian and the U.S. still posses the vast majority of the world’s nuclear weapons, the total number of warheads worldwide has dropped sharply:  there are roughly 15,000 today, down from around 70,000 in the 1980s.

But with renewed U.S.-Russian tensions again on the rise, and leaders from both nations pushing to rebuild their nation’s nuclear arsenals, the NPT faces its biggest challenge yet. That’s particularly worrisome given the pace of nuclear weapons development in North Korea and Iran, among the handful of countries not part of the deal and who pose a threat to the U.S.

Explore this collection of multimedia resources  produced by the Council on Foreign Relations and MediaStorm, to learn more about the history of the NPT and where it may be headed. It includes a series of interactive timelines and a map — View a full-screen version of the interactive here. Below that is a nuts-and-bolts rundown of the NPT and how it works, based on an analysis by the Nuclear Threat Initiative.

Who’s involved (and who isn’t)?

  • There are currently 190 state parties to the NPT, making it the most widely adhered-to arms control treaty to date.
  • The NPT designates five parties as nuclear-weapon states (NWS): China, France, the Soviet Union, the United Kingdom, and the United States.  These are nations that exploded a nuclear device before January 1, 1967. The 185  others are classified as non-nuclear-weapon states (NNWS). The NPT is effectively a “grand bargain” between the nuclear “haves” and “have-nots.”
  • Only four states have not signed the treaty: India, Israel, Pakistan, and newly independent South Sudan. South Sudan is not believed to have ever attempted to acquire nuclear weapons. The other three states possess nuclear weapons, but because they did not detonate a nuclear explosive device before January 1, 1967, they are not considered NWS under the NPT. Joining the NPT would require them to accept comprehensive IAEA safeguards, eliminate their nuclear arsenals, and join the treaty as NNWS. Precedent for this exists, as South Africa renounced its nuclear weapons and joined the NPT as an NNWS in 1991.
  • North Korea is the only country to date to withdraw from the NPT. North Korea initially announced its withdrawal from the treaty on March 12, 1993, but subsequently “suspended [its] effectuation.”[v] The second withdrawal decision was announced on January 10, 2003.

What was the NPT created to do?

  • The treaty aims to prevent the spread of nuclear weapons to additional countries while ensuring non-nuclear weapon state parties fair access to peaceful nuclear technology under international safeguards (audits and inspections.)
  • The NPT has three “pillars” or core objectives: disarmament, nonproliferation, and peaceful uses of nuclear technology.
  • Complete elimination of nuclear weapons is the treaty’s ultimate goal, leading to general and complete disarmament. That goal has never been attained.
  • As part of the treaty, the five nuclear states agree to not transfer nuclear weapons to non-nuclear states or encourage them to acquire these weapons; not provide them with any nuclear material for peaceful purposes or technology for its production, except under certain circumstances, must pursue, together with other parties to the treaty, “negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament,” and  pursue negotiations on a legally-binding treaty on general and complete disarmament.
  • The non-nuclear signatories agree to not build, acquire, possess, or seek to obtain nuclear weapons or receive transfers of nuclear weapons or any other nuclear explosive devices from anyone; they can still develop peaceful nuclear technology, but must agree to international inspections to verify that they are not diverted to nuclear weapons purposes.

How is the treaty upheld?

  • Every five years, state parties gather for a review conference to assess the implementation of the treaty and identify future steps and priorities. States who believe that the treaty jeopardizes their supreme national interests may withdraw from the NPT. But they must give notice to other parties of the NPT and the United Nations Security Council. Their withdrawal enters into force three months after this advance notice.

How to Stop a Nuclear War: The Non-Proliferation Treaty, Explained 23 April,2018Matthew Green


Matthew Green

Matthew Green is a digital media producer for KQED News. He previously produced The Lowdown, KQED’s multimedia news education blog. Matthew's written for numerous Bay Area publications, including the Oakland Tribune and San Francisco Chronicle. He also taught journalism classes at Fremont High School in East Oakland.

Email:; Twitter: @MGreenKQED

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