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Nuclear-Weapon-Free Zones (NWFZ) At a Glance

Arms Control Association
Nuclear/Ballistic Missile Nonproliferation
Fact Sheet, November 2007

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A nuclear-weapon-free zone (NWFZ) is a specified region in which countries commit themselves not to manufacture, acquire, test, or possess nuclear weapons. Three such zones exist today, and two others have been negotiated but have yet to enter into force. Countries in Latin America (the 1967 Treaty of Tlatelolco), the South Pacific (the 1985 Treaty of Rarotonga), and Southeast Asia (the 1995 Treaty of Bangkok) have all forsworn nuclear weapons. African countries also agreed to prohibit nuclear weapons on their continent, but the 1996 Treaty of Pelindaba has not entered into force. Most recently, five countries of the former Soviet Union in September 2006 signed the Central Asian nuclear-weapon-free zone, which has yet to enter into force.

Article VII of the nuclear Nonproliferation Treaty (NPT), which entered into force in 1970, affirms the right of countries to establish specified zones free of nuclear weapons. The UN General Assembly reaffirmed that right in 1975 and outlined the criteria for such zones. Within these nuclear-weapon-free zones, countries may use nuclear energy for peaceful purposes.

Each treaty establishing a nuclear-weapon-free zone includes a protocol for the five nuclear-weapon states recognized under the NPT-China, France, Russia, the United Kingdom, and the United States-to sign and ratify. These protocols, which are legally binding, call upon the nuclear-weapon states to respect the status of the zones and not to use or threaten to use nuclear weapons against treaty states-parties. Such declarations of non-use of nuclear weapons are referred to as negative security assurances. However, the five nuclear-armed countries have at times signed and ratified a NWFZ protocol and declared conditions reserving the right to use nuclear weapons in certain scenarios against parties to a nuclear-weapon-free zone. For instance, the United States signed the protocol for the African nuclear-weapon-free zone in April 1996 with a declaration that it would reserve the right to respond with all options, implying possible use of nuclear weapons, to a chemical or biological weapons attack by a member of the zone. None of the nuclear-weapon states have signed the relevant protocol for the treaty creating a zone in Southeast Asia because of concerns that it conflicts with the right of their ships and aircraft to have freedom of movement in international waters and airspace. The other three zones do not explicitly rule out the transit of nuclear weapons by nuclear-weapon states through the zones, and the general practice of nuclear-weapon states is not to declare whether nuclear weapons are aboard their vessels.

In addition to nuclear-weapon-free zones, there are treaties, which are not covered by this fact sheet, banning the deployment of nuclear weapons in Antarctica, Mongolia, on the seabed, and in outer space.

Basic Elements of Nuclear-Weapon-Free Zone Treaties

Duration: The treaties are to remain in force indefinitely. Yet, each treaty includes a withdrawal option for states-parties. With the exception of the Treaty of Tlatelolco, which simply requires three months' advance notice before a withdrawal can take effect, all the NWFZ treaties require 12 months' advance notice for a state-party to end its treaty obligations.

Conditions: None of the treaties can be subjected to conditions by its non-nuclear-weapon states-parties.

Verification: Each state-party adopts comprehensive safeguards administered by the International Atomic Energy Agency, which verifies that states-parties are not pursuing nuclear weapons illicitly.

Territory Covered: Each zone applies to the entire territories of all of its states-parties. Territory is understood to include all land holdings, internal waters, territorial seas, and archipelagic waters. The Latin American treaty also extends hundreds of kilometers from the states-parties' territories into the Pacific and Atlantic Oceans, but the nuclear-weapon states, citing their freedom at sea, assert that this does not apply to their ships and aircraft that might be carrying nuclear weapons. A dispute also exists over the inclusion of the Chagos Archipelago, which includes the U.S. military base at Diego Garcia in the Indian Ocean, as part of the proposed African nuclear-weapon-free zone. Neither the United States nor the United Kingdom recognizes Diego Garcia as being subject to the Pelindaba Treaty.


Initial efforts to create an area free of nuclear weapons began in the late 1950s with several proposals to establish such a zone in Central and Eastern Europe. Poland offered the first proposal-named the Rapacki Plan after the Polish foreign minister-in 1958. The Rapacki Plan sought to initially keep nuclear weapons from being deployed in Poland, Czechoslovakia, West Germany, and East Germany, while reserving the right for other European countries to follow suit. The Soviet Union, Sweden, Finland, Romania, and Bulgaria also floated similar proposals. All these early efforts, however, floundered amidst the U.S.-Soviet superpower conflict, although the Rapacki Plan would serve as a model to the nuclear-weapon-free zones that were eventually set up in other regions of the globe.

The Treaty of Tlatelolco (Latin America and the Caribbean)

Opened for signature: February 14, 1967
Entered into force: October 23, 2002[1]
States-parties: 33 total; Antigua and Barbuda, Argentina, Bahamas, Barbados, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominica, Dominican Republic, Ecuador, El Salvador, Grenada, Guatemala, Guyana, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Paraguay, Peru, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and Grenadines, Suriname, Trinidad and Tobago, Uruguay, and Venezuela.
Protocol ratification by nuclear-weapon states: Protocol II (negative security assurances) ratified by China, France, the United Kingdom, the United States, and the Soviet Union.[2]

The Treaty of Rarotonga (South Pacific)

Opened for signature: August 6, 1985
Entered into force: December 11, 1986
States-parties: 13 total; Australia, Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu.
Protocol ratification by nuclear-weapon states: Protocol II (negative security assurances) ratified by China, France, the United Kingdom, and the Soviet Union.[2] Protocol III (ban on nuclear testing in the nuclear-weapon-free zone) ratified by China, France, the United Kingdom, and the Soviet Union.[2]

The Treaty of Bangkok (Southeast Asia)

Opened for signature: December 15, 1995
Entered into force: March 27, 1997
State-parties: 10 total; Brunei Darussalam, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam.
Protocol ratification by nuclear-weapon states: None.

The Treaty of Pelindaba (Africa)

Opened for signature: April 11, 1996
Entered into force: The treaty has not entered into force, but it will once 28 signatories have completed ratification. Twenty-one of the 51 signatories have completed ratification.
States-parties: 0; Signatories that have ratified the treaty are Algeria, Botswana, Burkina Faso, Cote d'Ivoire, Equatorial Guinea, Gambia, Guinea, Kenya, Lesotho, Libya, Madagascar, Mali, Mauritania, Mauritius, Nigeria, Senegal, South Africa, Swaziland, Togo, United Republic of Tanzania, and Zimbabwe.
Protocol ratification by nuclear-weapon states: Protocol I (negative security assurances) ratified by China, France, and the United Kingdom. Protocol II (ban on nuclear testing in the nuclear-weapon-free zone) ratified by China, France, and the United Kingdom.

Central Asian Nuclear-Weapon-Free Zone Treaty

Opened for signature: September 8, 2006
Entered into force: The treaty has not entered into force, but it will once the remaining three signatories—Kazakhstan, Tajikistan, and Turkmenistan—complete ratification.
States-parties: 0; Signatories that have ratified the treaty are Kyrgyzstan and Uzbekstan.
Protocol ratification by nuclear-weapon states: None.


1. The treaty specified that the full zone would not enter into force until it was ratified by all states within the zones. That did not occur until Cuba ratified the treaty in 2002. However, the treaty permitted individual states to waive that provision and declare themselves bound by the treaty, which many did beginning in 1968.

2. Russia is recognized as inheriting the Soviet Union's treaty commitments.