The Non-Proliferation Treaty, NPT

When the Treaty of Non-Proliferation (NPT) opened up for signature in 1968, there were five nuclear weapon states in the world. At that time, there was a concern about how safe the world would be with more nuclear weapon states and therefore countries wanted to prevent proliferation to more states. The Cold War balance of terror between the US and Russia was unstable, and more actors with nuclear weapons would multiply the risks of using nuclear weapons, intentionally or accidentally.

The Nuclear Non-Proliferation Treaty (NPT) entered into force as international law in 1970, two years after it opened for signature. The idea was first proposed in 1958 when Ireland’s then Foreign Minister, Frank Aiken, suggested an agreement to regulate the proliferation and disarmament of nuclear weapons.

Although the agreement entered into force in 1970, it would take until 1992 for the last of the five “official” nuclear weapon states to sign the agreement through the signatures of France and China. Now the Non-Proliferation Treaty is one of the agreements with the highest accession, 191 states have joined today. North Korea left the agreement in 2003, but the UN Security Council has not accepted their withdrawal, so their status is still debated at the agreement’s conferences. The most notable of the countries outside the agreement are nuclear weapons states India, Israel, North Korea and Pakistan.

To have or not to have nuclear weapons

The Non-Proliferation Treaty divides State Parties into nuclear-weapon states and non-nuclear-weapon states. According to the agreement, those that had acquired nuclear weapons before January 1, 1967 are counted as official nuclear weapon states. These were China, France, the USSR (now Russia), the United Kingdom and the United States – coincidently these states are also the five permanent members of the UN Security Council (called the “P5”).

India, Israel, North Korea and Pakistan are continuously urged to give up their nuclear weapons and join the NPT as non-nuclear weapon states. The NPT gives State Parties the right to withdraw from the agreement with three months’ notice if the country is under an extraordinary state related to nuclear weapons which challenges the country’s highest interest. This has only happened once (North Korea) and states have not left the NPT despite conflict and invasion in the past.

Nuclear weapon states

Within the NPT, the nuclear weapon states undertake not to transfer nuclear weapons to other states. Nor may they assist or encourage non-nuclear weapon states to develop nuclear weapons. Non-nuclear weapon states, in turn, undertake not to receive or acquire nuclear weapons. This agreement is called “the grand bargain”.

The NPT imposes different requirements on nuclear weapon states and non-nuclear weapon states:

  • The countries that have nuclear weapons promise not to transfer nuclear weapons to any state or non-state actor. Nor may they assist or encourage non-nuclear weapon states to develop nuclear weapons. This means that any kind of trade in or distribution of nuclear weapons, nuclear weapon parts, technology or materials that enable new states to produce nuclear weapons is prohibited.
  • The agreement is also the only international legally binding agreement that stipulates that (the five) nuclear weapon states “undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control.” However, there is no time limit for when this should be done, in what order or how it should be done.

Non-nuclear weapon states

Non-Nuclear weapon states undertake not to receive or produce nuclear weapons. According to the agreement, all states have the right to peaceful nuclear technology, nuclear reactors, for energy production. Nuclear power reactors in non-nuclear weapon states must be inspected by the International Atomic Energy Agency, the IAEA, to check that no country is using its nuclear energy program to develop nuclear weapons.

The division into states that have nuclear weapons and states that do not, and will never have, has always been a source of frustration for some countries. The agreement was supposed to end in 1995, but the state parties chose to extend the agreement indefinitely because nuclear weapons still remained. The nuclear weapon states are criticized for not having fulfilled their commitments to disarm, when the non-nuclear weapon states have fulfilled their commitments not to acquire nuclear weapons. They are said to not be living up to their half of “the grand bargain.”

Three pillars

The Non-Proliferation Treaty is structured around three main issues:

  • Prevent proliferation of nuclear weapons to new actors
  • Disarmament of existing arsenals
  • Right to peaceful use of nuclear energy (nuclear power)


Countries tend to have different focus on these pillars. The nuclear weapon states underline the efforts they are making for disarmament and believe that the disarmament process is ongoing. They believe that the focus should therefore be on non-proliferation, which, in their view, is the major security issue.

The majority of the non-nuclear-weapon states often focus on disarmament. This, they believe, contributes to increased international security with a reduced risk of the spread of nuclear weapons. Disarmament of existing arsenals also reduces the risk of nuclear weapons being used, both intentionally and accidentally.

The third pillar on the peaceful use of nuclear technology is often criticized as many believe that nuclear power reactors provide the opportunity to create nuclear weapons. Used nuclear fuel contains plutonium that can be reprocessed into nuclear weapons material, and the same facilities that are being used to enrich uranium for nuclear reactors can be used to highly enrich uranium for nuclear weapons.

Others believe that the agreement could never have entered into force if this pillar had not been included. The agreement provides for inspections by the IAEA of nuclear facilities in non-nuclear weapon states, while no inspections are required of either nuclear weapons or nuclear power facilities in the nuclear-weapon states.

Review conferences

The agreement states that after 25 years the State Parties would gather in a conference to decide whether the NPT should be extended for a certain period or whether the agreement should be extended indefinitely. In 1995, the State Parties therefore met and decided that the agreement should be extended indefinitely.

Every five years, all State Parties of the Non-Proliferation Treaty meet for a Review Conference (NPT Review Conference or NPT RevCon). At the review conference, the State Parties evaluate how the agreement is being implemented and make decisions on how to better implement the commitments and negotiate an outcome document. As a rule, the Review Conferences make decisions by consensus. The State Parties take turns chairing the Review Conferences. A review conference lasts about a month. The most recent Review Conference was scheduled for 2020 but due to the global pandemic, it was held in August 2022. The next Review Conference will be held in 2025.

Preparatory Committees

Preparatory Committees (NPT PrepCom) are held every year between Review Conferences, except in the year immediately following a Review Conference. The preparatory committees bring together all the State Parties of the agreement and usually last about ten days. These meetings begin the discussions which will result in the Review Conference outcome documents.

The participation of civil society

Civil society organizations working on nuclear weapons always attend the NPT conferences. The general debate during both the Review Conferences and the Preparatory Committees is open to all. While other discussions usually take place behind closed doors where only the State Parties are allowed to participate. Civil society is given half a day to present its views and demands on the State Parties.

During the conferences, civil society including research institutes, religious groups, academics and the states arrange side events with seminars, workshops and presentations of reports to update, inform and develop the discussion around the NPT. Civil society also issues reports during the meetings to inform others on how the discussions are unfolding.

The civil society reports from these meetings fulfill an important function and put pressure on the State Parties to really implement what they have promised. Many organizations think that the work to implement the agreement is going too slowly, above all regarding the disarmament commitments of the nuclear-weapon states.

Sources and more information

Treaty on the Non-Proliferation of Nuclear Weapons (NPT), United Nations Office for Nuclear Disarmament, ODA
Timeline of the Treaty on the Non-Proliferation of Nuclear Weapons, NPT, Arms Control Association
Nuclear Non-Proliferation Treaty, Reaching Critical Will


Swedish Physicians Against Nuclear Weapons

Last updated
12 January, 2023