Treaty on the Non-Proliferation of Nuclear Weapons (NPT)

The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is a legally binding disarmament and non-proliferation treaty. Its goal is to prevent the proliferation of and ultimately abolish nuclear weapons while ensuring the peaceful use of nuclear energy.

What are nuclear weapons?

Nuclear weapons are nuclear explosive devices whose devastating effect on humans and the environment is based on the enormous energy released in the form of heat, pressure and radiation during nuclear fission or fusion. Nuclear weapons are considered weapons of mass destruction whose proliferation is regulated by the NPT.


The NPT and its three pillars reflect the commitment of the international community to reduce the risk of nuclear war and, in the longer term, to eliminate it altogether. To this end, access to nuclear weapons for further countries is to be denied (non-proliferation), existing arsenals are ultimately to be eliminated (disarmament), and the right to peaceful use of nuclear energy is to be guaranteed (peaceful use).


Within the NPT, a distinction is made between nuclear-weapon States and non-nuclear-weapon States. The former being those that had detonated a nuclear weapon prior to 1 January 1967. Based on this definition, the five NPT nuclear-weapon States (China, France, Russia, the United Kingdom, and the United States) are identical to the permanent members of the UN Security Council.

The NPT is based on a “grand bargain” between the two groups of States. Non-nuclear-weapons States commit themselves to renounce nuclear weapons and to allow safeguards by the International Atomic Energy Agency (IAEA). In return, all States agree to negotiate complete nuclear disarmament. Furthermore, the NPT guarantees the right to peaceful use of nuclear energy and the corresponding cooperation.

In terms of non-proliferation, the NPT has contributed to the fact that, in addition to the five NPT nuclear-weapon States, only four other States (India, Israel, North Korea, and Pakistan) have such weapons of mass destruction. In addition to IAEA safeguards, internationally harmonized export controls, such as those established by the Nuclear Suppliers Group (NSG), implement NPT non-proliferation obligations without preventing access to nuclear goods for the peaceful use of nuclear energy.

However, the NPT has so far been unable to achieve the goal of complete nuclear disarmament. Nuclear weapons are not banned under international law by the NPT. A Treaty on the Prohibition of Nuclear Weapons (TPNW), which provides for a ban on nuclear weapons and related activities, entered into force on 22 January 2021. Switzerland has not yet signed the TPNW.

NPT Member States

Karte NPT

NPT Key Info

  • Entry into force: 1970
  • Entry into force in Switzerland: 1977
  • Members: 190

Last modification 02.06.2021

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