Module 1:


The Treaty on the Non-Proliferation of Nuclear Weapons (also known as the Non-Proliferation Treaty or NPT) is the cornerstone of the international nuclear nonproliferation regime. The NPT embodies the international community’s efforts to prevent the further spread of nuclear weapons, and to cooperate in achieving a world free of these weapons. It also facilitates states’ pursuit of nuclear energy for peaceful purposes, and through the International Atomic Energy Agency (IAEA), has an extensive verification regime to ensure that non-nuclear-weapon states are in compliance with their obligations not to develop or obtain nuclear weapons.

NPT Quick Facts

  • The NPT opened for signature on July 1, 1968 and entered into force on March 5, 1970[i]
  • There are currently 190 state parties to the NPT,[ii] making it the most widely adhered-to arms control treaty to date
  • The NPT designates 5 parties as nuclear-weapon states (NWS), while all others are classified as non-nuclear-weapon states (NNWS); states’ obligations and privileges under the treaty differ based on their classification
  • The NPT is commonly perceived to have three “pillars” or core objectives: disarmament, nonproliferation, and peaceful uses of nuclear technology
  • 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)
  • Complete elimination of nuclear weapons is the treaty’s ultimate goal, leading to general and complete disarmament
  • Only four states have not signed the treaty: India, Israel, Pakistan, and newly independent South Sudan.[iii] 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[iv]
  • 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[vi]

Why Is The NPT Important?

  • The NPT is an indispensable legal and political instrument to prevent the further proliferation of nuclear weapons. In the absence of the NPT, it is likely that many other countries would have developed nuclear weapons post-1970, sparking regional and global arms races
  • Without NPT safeguards requirements, monitoring and inspection of nuclear materials and facilities in non-nuclear weapon states would be significantly weakened
  • The NPT is the only treaty that legally binds the five officially recognized nuclear weapon states (China, France, Russia, the United Kingdom, and the United States) to pursuing nuclear disarmament

How Does The NPT Work?

Parties to the treaty consist of the five nuclear weapon states (NWS) and the 185 non-nuclear weapon states (NNWS), with respective rights and responsibilities. The NPT is effectively a “grand bargain” between the nuclear “haves” and “have-nots.”

Nuclear Weapon States (NWS):

  • The five states who exploded a nuclear device before January 1, 1967 (China; France; the Soviet Union—now Russia; the United States; and the United Kingdom)
  • May not transfer nuclear weapons to NNWS (Art. I)
  • May not assist or encourage any NNWS to acquire or manufacture nuclear weapons (Art. I)
  • May not provide nuclear material for peaceful purposes or technology for its production to NNWS unless it is placed under safeguards (Art. III)
  • 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 to pursue negotiations on a legally-binding treaty on general and complete disarmament (Art. VI)

Non-Nuclear Weapon States (NNWS):

  • Must not build, acquire, possess, or seek to obtain nuclear weapons (Art. II)
  • May not receive transfers of nuclear weapons or any other nuclear explosive devices from anyone (Art. II)
  • Maintain an “inalienable right” to research, produce, and use nuclear energy for peaceful purposes (Art. IV)
  • Must accept IAEA safeguards (audits, monitoring and inspections) on all of their peaceful nuclear activities and materials to verify that they are not diverted to nuclear weapons purposes (Art. III)
  • Must pursue, together with other parties, negotiations in good faith towards ending the nuclear arms race and achieving nuclear disarmament (Art. VI)

Every five years, in accordance with Article VIII, state parties gather for a review conference to assess the implementation of the treaty and identify future steps and priorities. Under Article X, states who believe that the treaty jeopardizes their supreme national interests may withdraw from the NPT. They must give notice to other parties of the NPT and the United Nations Security Council, and their withdrawal enters into force three months after this advance notice.

What Are The NPT’s Three Pillars?

The NPT is commonly perceived to have three “pillars” or core objectives: disarmament, nonproliferation, and peaceful uses of nuclear technology


  • Article VI: Commits state parties to pursue negotiations in good faith toward ending the nuclear arms race and achieving nuclear disarmament; promotes general and complete disarmament


  • Article I: Forbids the five NWS from transferring their nuclear weapons to any other state or aiding NNWS in acquiring nuclear weapons
  • Article II: Forbids NNWS from developing, seeking, or acquiring nuclear weapons
  • Article III: Requires NNWS to accept IAEA safeguards to ensure that nuclear materials for civil uses will not be diverted to nuclear weapons or other nuclear explosive devices

Peaceful uses of nuclear technology

  • Article IV: Acknowledges the inalienable right of state parties to the NPT to use nuclear technology for peaceful purposes. These endeavors must be in compliance with Articles I and II of the NPT.

View the full-text version of the treaty.[vii]


[i] “Treaty on the Non-proliferation of Nuclear Weapons (NPT)”.

[ii] United Nations, “Treaty on the Non-proliferation of Nuclear Weapons,” Disarmament Treaties Database. United Nations Office for Disarmament Affairs, 2013,

[iii] “Treaty on the Non-proliferation of Nuclear Weapons (NPT)”.

[iv] “IAEA Safeguards: Stemming the Spread of Nuclear Weapons,” International Atomic Energy Agency,

[v] See “IAEA and DPRK: Factsheet on DPRK Nuclear Safeguards,” International Atomic Energy Agency,

[vi] Jean du Preez and William Potter, “North Korea’s Withdrawal from the NPT: A Reality Check,” James Martin Center for Nonproliferation Studies. Monterey Institute of International Studies, April 8, 2003,

[vii] “Treaty on the Non-proliferation of Nuclear Weapons (NPT),” Center for Nonproliferation Studies,