The Antarctic Treaty
Scientific interests, rather than political, economic, or military concerns, dominated the expeditions sent to Antarctica after World War II. International scientific associations were able to work out arrangements for effective cooperation. On 3 May 1958, the United States proposed a conference to consider the points of agreement that had been reached in informal multilateral discussions. Specifically, the Conference sought to formalize international recognition that:

• The legal status quo of the Antarctic Continent would remain unchanged;
  
  
• The cooperation of the scientific community would continue; and
  
  
• The continent would be used for peaceful purposes only.

The Washington Conference on Antarctica culminated in a treaty signed on 1 December 1959. The Treaty entered into force on 23 June 1961, when the formal ratifications of all the participating nations had been received.

The Treaty provides that Antarctica shall be used for peaceful purposes only. It specifically prohibits “any measures of a military nature, such as the establishment of military bases and fortifications, the carrying out of military maneuvers, as well as the testing of any type of weapons.” Military personnel or equipment, however, may be used for scientific research or for any other peaceful purpose. Nuclear explosions and the disposal of radioactive waste material in Antarctica are prohibited, subject to certain future international agreements on these subjects. There are provisions for amending the Treaty, for referring disputes that cannot be handled by direct talks, mediation, arbitration, or other peaceful means to the International Court of Justice, as well as for calling a conference in 30 years to review the operation of the Treaty if any parties so request. back to chart

The Treaty for the Prohibition of Nuclear Weapons in Latin America
(Treaty of Tlatelolco)
The idea of a Latin American Nuclear Weapons-Free Zone was first introduced to the United Nations (U.N.) General Assembly in 1962. On 27 November 1963, this declaration received the support of the U.N. General Assembly, with the United States voting in the affirmative.

On 14 February 1967, the Treaty was signed at a regional meeting of Latin American countries in Tlatelolco, which is a section of Mexico City. As specified in Article 28, when all eligible States ratify the Treaty, it will enter into force for all of them. Alternatively, under that Article, any Latin American State may bring the Treaty into force for itself at any time by waiving that provision.

The basic obligations of the Treaty are contained in Article I:

• The contracting parties undertake to use exclusively for peaceful purposes the nuclear material and facilities which are under their jurisdiction, and to prohibit and prevent in their respective territories: the testing, use, manufacture, production, receipt, storage, installation, deployment, or acquisition by any means whatsoever of any nuclear weapons by the parties themselves, directly or indirectly, on behalf of anyone else or in any other way; and
  
  
• In Protocol II of the Treaty, States outside of Latin America undertake: to respect the denuclearized status of the zone; not to contribute to acts involving violation of obligations of the parties; and not to use or threaten to use nuclear weapons against the contracting parties.

The United States ratified the Protocol II on 8 May 1971, and deposited the instrument of ratification on 12 May 1971, subject to several understandings and declarations. France, the United Kingdom, China, and Russia are also parties to Protocol II. back to chart

South Pacific Nuclear-Free Zone Treaty (Treaty of Rarotonga)
On 6 August 1985, the South Pacific Forum, a body comprising the independent and self governing countries of the South Pacific (Australia, the Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue Island, Papua New Guinea, the Solomon Islands, Tonga, Tuvalu, Vanuatu, and Western Samoa), endorsed the text of the South Pacific Nuclear-Free Zone Treaty and opened it for signature.

The Treaty is in force for 12 of the 15 South Pacific Forum members. The United States, the United Kingdom, France, Russia, and China have all signed the Protocols which directly pertain to them.

The Parties to the Treaty agreed:

• Not to manufacture or otherwise acquire, possess, or have control over any nuclear explosive device by any means anywhere inside or outside the South Pacific Nuclear-Free Zone;
  
  
• Not to seek or receive any assistance in the manufacture or acquisition of any nuclear explosive device;
  
  
• To prevent in its territory the stationing of any nuclear explosive device;
  
  
• To prevent in its territory the testing of any nuclear explosive device; and
  
  
• Not to take any action to assist or encourage the testing of any nuclear explosivedevice by any State. back to chart

Treaty on the Southeast Asia Nuclear Weapons-FreeZone (Bangkok Treaty)
Indonesia and Malaysia originally proposed the establishment of a Southeast Asia Nuclear Weapons-Free Zone in the mid-1980s. On 15 December 1995, 10 Southeast Asian States signed the Southeast Asian Nuclear Weapons-Free Zone Treaty at the Association of Southeast Asian Nations (ASEAN) Summit in Bangkok.

The Treaty commits parties not to conduct, receive, or give assistance in the research, development, manufacture, stockpiling, acquisition, possession, or control over any nuclear explosive device by any means. Each State Party also undertakes not to dump at sea or discharge into the atmosphere anywhere within the Zone any radioactive material or wastes. Under the Treaty Protocol, each State Party undertakes not to use or threaten to use nuclear weapons against any State Party to the Treaty, and not to use or threaten to use nuclear weapons within the Zone.

The United States has not signed the Bangkok Treaty. back to chart

African Nuclear Weapons-Free Zone Treaty (Pelindaba Treaty)
The Organization of African Unity (OAU) first formally enunciated the desire to draft a treaty ensuring the denuclearization of Africa in July 1964. No real progress was made until South Africa joined the Nuclear Non-Proliferation Treaty (NPT) in 1991. In April 1993, a group of U.N. and OAU experts convened to begin drafting a treaty.

The Pelindaba Treaty commits parties not to conduct or receive or give assistance in the research, development, manufacture, stockpiling, acquisition, possession, or control over any nuclear explosive device by any means anywhere.

The Treaty was opened for signature on 11 April 1996. The United States, the United Kingdom, France, China, and Russia have all signed the relevant protocols to the Treaty. The United States was eligible to sign the non-use and non-testing protocols only, because it has no territories for which it is internationally responsible in the African region. back to chart

Limited Test Ban Treaty (LTBT)
The Limited Test Ban Treaty (LTBT) of 1963 prohibits nuclear weapons tests “or any other nuclear explosion” in the atmosphere, in outer space, and under water. While the Treaty does not ban tests under ground, it does prohibit nuclear explosions in this environment if they cause “radioactive debris to be present outside the territorial limits of the State under whose jurisdiction or control” the explosions were conducted. In accepting limitations on testing, the nuclear powers accepted as a common goal “an end to the contamination of the environment by radioactive substances.”

The LTBT is of unlimited duration. The Treaty is open to all states, and most of the countries of the world are parties to it. The Treaty has not been signed by France or the People's Republic of China (PRC). back to chart

Nuclear Non-Proliferation Treaty (NPT)
In 1968, the United States signed the Nuclear Non-Proliferation Treaty (NPT). It forms the cornerstone of the international nuclear nonproliferation regime and most nations of the world are parties to the Treaty. The NPT recognizes the five nuclear powers that existed in 1968: the United States, Russia, the United Kingdom, France, and China. The Treaty prohibits all other signatories, including Iran, Iraq, Libya, and North Korea (In January 2003, the Democratic People’s Republic of Korea formally withdrew from the NPT) from acquiring or even pursuing a nuclear weapons capability. This requirement has prevented some states from signing the NPT, including Brazil, India, Israel, Cuba, and Pakistan. These nations oppose the inherent double standard in the Treaty and argue that all nations should renounce nuclear weapons.

While the non-nuclear signatories to the NPT are prohibited from developing nuclear weapons, the Nuclear Weapons States are obligated to assist them in acquiring peaceful applications for nuclear technology.

In broad outline, the basic provisions of the Treaty are designed to:

• Prevent the spread of nuclear weapons (Articles I and II);
  
  
• Provide assurance, through international safeguards, that the peaceful nuclear activities of States which have not already developed nuclear weapons will not be diverted to making such weapons (Article III);
  
  
• Promote, to the maximum extent consistent with the other purposes of the Treaty, the peaceful uses of nuclear energy, including the potential benefits of any peaceful application of nuclear technology to be made available to non-nuclear parties under appropriate international observation (Article IV-V); and
  
  
• Express the determination of the parties that the Treaty should lead to further progress in comprehensive arms control and nuclear disarmament measures
  (Article VI).

In accordance with the terms of the NPT, a conference was held in 1995 to decide whether the NPT should continue in force indefinitely or be extended for an additional fixed period or periods. On 11 May 1995, more than 170 countries attending the NPT Review and Extension Conference in New York decided to extend the Treaty indefinitely and without conditions. back to chart

Strategic Arms Limitation Talks (SALT)
The first series of Strategic Arms Limitation Talks extended from November 1969 to May 1972. During that period, the United States and the Soviet Union negotiated the first agreements to place limits and restraints on some of their most important nuclear armaments.

At the time, American and Soviet weapons systems were far from symmetrical. Further, the defense needs and commitments of the two superpowers differed considerably. The United States had obligations for the defense of Allies overseas, such as Western Europe and Japan, while the Soviet Union’s allies were its near neighbors. All these circumstances made for difficulties in equating specific weapons, or categories of weapons, and in defining overall strategic equivalence.

In a summit meeting in Moscow, after two and a half years of negotiation, the first round of SALT was brought to a conclusion on 26 May 1972, when President Richard M. Nixon and General Secretary Leonid Brezhnev signed the Anti-Ballistic Missile (ABM) Treaty and theInterim Agreement on Strategic Offensive Arms. back to chart

Anti-Ballistic Missile (ABM) Treaty
In the Treaty on the Limitation of Anti-Ballistic Missile (ABM) Systems, the United States and the Soviet Union agreed that each party may have only two ABM deployment areas, restricted and located to preclude providing a nationwide ABM defense or from becoming the basis for developing one. Each country thus agreed not to challenge the penetration capability of the other’s retaliatory nuclear missile forces.

The Treaty permitted each side to have one ABM system to protect its capital and another to protect one ICBM launch area. The two sites defended had to be at least 1,300 kilometers apart to prevent the creation of any effective regional defense zone or the beginnings of a nationwide system.

Precise quantitative and qualitative limits were imposed on the ABM systems deployed. Further, to decrease the pressures of technological change and its unsettling impact on the strategic balance, both sides agreed to prohibit the development, testing, or deployment of sea-based, air-based, or space-based ABM systems and their components, along with mobile land-based ABM systems. Should future technology bring forth new ABM systems “based on other physical principles” than those employed in then-current systems, it was agreed that limiting such systems would be discussed, in accordance with the Treaty’s provisions for consultation and amendment.

In June 2002, the United States withdrew from the ABM Treaty to pursue a ballistic missile defense program. back to chart

Interim Agreement on Strategic Offensive Arms (SALT I Treaty)
As its title suggests, the “Interim Agreement Between the United States and the Union of Soviet Socialist Republics on Certain Measures With Respect to the Limitation of Offensive Arms” was limited in duration and scope. It was intended to remain in force for only five years. Both countries agreed to continue negotiations toward a more comprehensive agreement as soon as possible. The scope and terms of any new agreement were not to be prejudiced by the provisions of the 1972 interim accord.

Thus, the Interim Agreement was intended as a holding action, which was designed to complement the ABM Treaty by limiting competition in offensive strategic arms and by providing time for further negotiations. The Agreement essentially froze existing levels of strategic ballistic missile launchers (operational or under construction) for both sides. It permitted an increase in SLBM launchers up to an agreed level for each party only with the dismantling or destruction of a corresponding number of older ICBM or SLBM launchers.

In view of the many asymmetries between the United States and the Soviet Union, imposing equivalent limitations required complex and precise provisions. At the date of signing, the United States had 1,054 operational land-based ICBMs, with none under construction; the Soviet Union had an estimated 1,618 ICBMs including operational missiles and those under construction. Launchers under construction were permitted to be completed. Neither side would start construction of additional fixed land-based ICBM launchers during the period of the Agreement, in effect, excluding the relocation of existing launchers. Launchers for light or older ICBMs could not be converted into launchers for modern heavy ICBMs. This prevented the Soviet Union from replacing older missiles with missiles such as the SS-9, which in 1972, was the largest and most powerful missile in the Soviet inventory and a source of particular concern to the United States.

Within these limitations, modernization and replacements were permitted, but in the process of modernizing, the dimensions of silo launchers could not be significantly increased. Mobile ICBMs were not covered. back to chart

SALT II
In accordance with Article VII of the Interim Agreement, in which the sides committed themselves to continue active negotiations on strategic offensive arms, the SALT II negotiations began in November 1972. The primary goal of SALT II was to replace the Interim Agreement with a long-term, comprehensive treaty providing broad limits on strategic offensive weapons systems. The principal U.S. objectives as the SALT II negotiations began were: to provide for equal numbers of strategic nuclear delivery vehicles for the two sides; to begin the process of reducing the number of these delivery vehicles; and to impose restraints on qualitative developments which could threaten future stability.

Early discussion focused on: the weapon systems to be included; factors involved in providing for equality in numbers of strategic nuclear delivery vehicles, taking into account the important differences between the forces of the two sides; bans on new systems; qualitative limits; and a Soviet proposal to include U.S. forward-based systems. The positions of the sides differed widely on many of these issues. In subsequent negotiations, the sides agreed
on a general framework for SALT II.

The Treaty included detailed definitions of limited systems, provisions to enhance verification, a ban on circumvention of the provisions of the Agreement, and a provision outlining the duties of the Security Council in connection with the SALT II Treaty. The duration of the Treaty was to have been through 1985.

The completed SALT II agreement was signed by President James E. Carter and General Secretary Leonid Brezhnev in Vienna on 18 June 1979. President Carter transmitted it to the Senate on 22 June for ratification. U.S. ratification of SALT II was delayed because of the Soviet invasion of Afghanistan. Although the Treaty remained unratified, each party was individually bound under international law to refrain from acts which would defeat the object and purpose of the Treaty, until it had made its intentions clear not to become a party to the Treaty.

SALT II has never entered into force. back to chart

Threshold Test Ban Treaty (TTBT)
The Treaty on the Limitation of Underground Nuclear Weapon Tests, also known as the Threshold Test Ban Treaty (TTBT), was signed in July 1974. It established a nuclear “threshold,” by prohibiting tests with a yield exceeding 150 kilotons (equivalent to 150,000 tons of TNT).

The mutual restraint imposed by the Treaty reduced the explosive force of new nuclear warheads and bombs. Particularly significant at the time was the relationship between the explosive power of reliable, tested warheads and a first-strike capability.

The TTBT included a Protocol detailing the technical data to be exchanged and limiting weapon testing to specific designated test sites which would assist verification efforts. The data to be exchanged included information on the geographical boundaries and geology of the testing areas. Geological data, including such factors as density of rock formation, water saturation, and depth of the water table, are useful in verifying test yields, because the seismic signal produced by a given underground nuclear explosion varies with these factors at the test location. After an actual test has taken place, the geographic coordinates of the test location were to be furnished to the other party, to help in placing the test in the proper geological setting and in assessing the yield.

The Treaty also stipulated that data would be exchanged on a certain number of tests for calibration purposes. By establishing the correlation between the stated yield of an explosion at the specified sites and the seismic signals produced, this exchange improved assessments by both parties of the yields of explosions based primarily on the measurements derived from their seismic instruments.

Although the TTBT was signed in 1974, it was not sent to the U.S. Senate for ratification until July 1976. Submission was held in abeyance until the companion Treaty on Underground Nuclear Explosions for Peaceful Purposes had been successfully negotiated in accordance with Article III of the TTBT.

For many years, neither the United States nor the Soviet Union ratified the TTBT or the PNE Treaty. However, in 1976, each party separately announced its intention to observe the Treaty limit of 150 kilotons, pending ratification.

The United States and the Soviet Union began negotiations in November 1987 to reach agreement on additional verification provisions that would make it possible for the United States to ratify the two Treaties. Agreement on additional verification provisions, contained in new protocols substituting for the original protocols, was reached in June 1990. The TTBT and PNE Treaty both entered into force on 11 December 1990. back to chart

Peaceful Nuclear Explosion (PNE) Treaty
In preparing the TTBT, the United States and the Soviet Union recognized the need to establish an appropriate agreement to govern underground nuclear explosions for peaceful purposes.

In the Peaceful Nuclear Explosion (PNE) Treaty, the United States and the Soviet Union agreed:

• Not to carry out any individual nuclear explosions with a yield exceeding 150 kilotons;
  
  
• Not to carry out any group explosion (consisting of a number of individual explosions) with an aggregate yield exceeding 1,500 kilotons; and
  
  
• Not to carry out any group explosion with an aggregate yield exceeding 150 kilotons unless the individual explosions in the group could be identified and measured by agreed verification procedures.

The parties reserved the right to carry out nuclear explosions for peaceful purposes in the territory of another country if requested to do so, but only in full compliance with the yield limitations and other provisions of the PNE Treaty and in accordance with the NPT.

The Protocol to the PNE Treaty sets forth the specific agreed arrangements for ensuring that no weapons-related benefits precluded by the TTBT are derived by carrying out a nuclear explosion used for peaceful purposes.

The agreed statement that accompanies the PNE Treaty specifies that a “peaceful application” of an underground nuclear explosion would not include the developmental testing of any nuclear explosive. Nuclear explosive testing must be carried out at the nuclear weapon test sites specified by the terms of the TTBT and would be treated as the testing of a nuclear weapon.

The provisions of the PNE Treaty, together with those of the TTBT, establish a comprehensive system of regulations to govern all underground nuclear explosions of the United States and the Soviet Union. The interrelationship of the TTBT and the PNE Treaty is further demonstrated by the provision that neither party may withdraw from the PNE Treaty while the TTBT remains in force. Conversely, either party may withdraw from the PNE Treaty upon termination of the TTBT.

The PNE Treaty and the TTBT both entered into force on 11 December 1990. back to chart

Intermediate-Range Nuclear Forces (INF) Treaty
The Treaty Between the United States of America and the Union of Soviet Socialist Republics on the Elimination of Their Intermediate-Range and Shorter-Range Missiles, commonly referred to as the Intermediate-Range Nuclear Forces (INF) Treaty, requires the destruction of ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers, their launchers and associated support structures and support equipment within three years after the Treaty enters into force.

On 8 December 1987, the Treaty was signed by President Ronald Reagan and General Secretary Mikhail Gorbachev at a summit meeting in Washington. At the time of its signature, the Treaty’s verification regime was the most detailed and stringent in the history of nuclear arms control. It was designed to eliminate all declared INF systems within three years of the Treaty’s entry into force and also to ensure compliance with the total ban on possession and use of these missiles.

The Treaty entered into force upon the exchange of instruments of ratification in Moscow on 1 June 1988.

In late April and early May 1991 the United States eliminated its last ground-launched cruise missile and ground-launched ballistic missile covered under the INF Treaty. The last declared Soviet SS-20 was eliminated on 11 May 1991. In total, 2,692 missiles were eliminated after the Treaty’s entry into force.

Following the 25 December 1991, dissolution of the Soviet Union, the United States sought to secure continuation of full implementation of the INF Treaty regime and to multilateralize the INF Treaty with the twelve former Soviet Republics.

The multilateralizing of what was previously a bilateral U.S.-Soviet INF Treaty required establishing agreements between the United States and the governments of the relevant Soviet successor States on numerous issues. Among the tasks undertaken were: arrangements for the settlement of costs connected with implementation activities in the new, multilateral Treaty context; the establishment of new points of entry in Belarus, Kazakhstan, and Ukraine through which to conduct inspections of the former INF facilities in those countries; and the establishment of communications links between the United States and those countries for the transmission of various Treaty-related notifications.
back to chart

Strategic Arms Reduction Treaty (START) I
After nine years of negotiations, the START I Treaty was signed in Moscow on 31 July 1991. Five months later, the Soviet Union dissolved and four independent States with strategic nuclear weapons on their territories came into existence: Belarus, Kazakhstan, Russia, and
Ukraine.

Through the Lisbon Protocol to the START I Treaty signed on 23 May 1992, Belarus, Kazakhstan, Russia, and Ukraine became Parties to the START I Treaty as legal successors to the Soviet Union. In December 1994, the Parties to the START I Treaty exchanged instruments of ratification, and START I entered into force.

START I requires reductions in strategic offensive arms to equal aggregate levels, from a high of some 10,500 in each arsenal. The central limits include:

• 1,600 strategic nuclear delivery vehicles;
  
  
• 6,000 accountable warheads;
  
  
• 4,900 ballistic missile warheads;
  
  
• 1,540 warheads on 154 heavy ICBMs; and
  
  
• 1,100 warheads on mobile ICBMs.

While the Treaty calls for these reductions to be carried out over seven years; in practice, all the Lisbon Protocol signatories began deactivating and eliminating systems covered by the Agreement prior to its entry into force.

START I has a 15-year duration and can be extended for successive five-year periods by agreement among the parties. START I was negotiated with effective verification in mind. The basic structure of the Treaty is designed to facilitate verification by National Technical Means (NTM). The Treaty contains detailed, mutually-reinforcing verification provisions to supplement NTM.

On 5 December 1991, the United States and Russia announced that they had met final START I requirements. This completed the largest arms control reductions in history. back to chart

Strategic Arms Reduction Treaty (START) II
Negotiations to achieve a follow-on to START I began in June 1992. The United States and Russia agreed on the text of a Joint Understanding on the Elimination of MIRVed ICBMS and Further Reductions in Strategic Offensive Arms. The Joint Understanding called for both sides to promptly conclude a new treaty that would further reduce strategic offensive arms by eliminating all MIRVed ICBMs (including all heavy ICBMs), limit the number of SLBM warheads to no more than 1,750, and reduce the overall total number of warheads for each side to between 3,000 and 3,500.

On 3 January 1993, President George H.W. Bush and President Boris Yeltsin signed the Treaty Between the United States of America and the Russian Federation on Further Reduction and Limitation of Strategic Offensive Arms. The Treaty, often called START II, codifies the Joint
Understanding signed by the two Presidents at the Washington Summit on 17 June 1992.

The 1993 START II Treaty never entered into force because of the long delay in Russian ratification and because Russia conditioned its ratification of START II on preservation of the ABM Treaty. back to chart

1991 Presidential Nuclear Initiatives
On 17 September 1991, President George H.W. Bush announced that the United States would eliminate its entire, worldwide inventory of ground-launched tactical nuclear weapons and would remove tactical nuclear weapons from all U.S. Navy surface ships, attack submarines, and land-based naval aircraft bases. In addition, President Bush declared that U.S. strategic bombers would be taken off alert and that ICBMs scheduled for deactivation under START I would also be taken off alert.

These unilateral arms reductions are known as the 1991 Presidential Nuclear Initiatives.
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Comprehensive Test Ban Treaty (CTBT)
The Comprehensive Test Ban Treaty (CTBT) was negotiated at the Geneva Conference on Disarmament (CD) between January 1994 and August 1996. The United Nations General Assembly voted on 10 September 1996, to adopt the Treaty by a vote of 158 in favor, three opposed, and five abstentions. President William J. Clinton was the first world leader to sign the CTBT on 24 September 1996. The CTBT bans any nuclear weapon test explosion or any other nuclear explosion. The CTBT is of unlimited duration. Each State Party has the right to withdraw from the CTBT under the standard “supreme national interest” clause. President Clinton submitted the Treaty to the U.S. Senate for ratification, but the Senate rejected the Treaty by a vote of 51 to 48.

Despite the fact that the Treaty has not been ratified, and therefore has not entered into force, the United States continues to observe a self-imposed moratorium on underground nuclear testing, which began in 1992. back to chart

Strategic Offensive Reductions Treaty (SORT) (The Moscow Treaty)
On 24 May 2002, U.S. President George W. Bush and Russian President Vladimir Putin signed the Moscow Treaty on Strategic Offensive Reductions. Under the terms of this Treaty, the United States and Russia will reduce their operationally-deployed strategic nuclear warheads to a level between 1,700 and 2,200 by 31 December 2012, nearly two-thirds below current levels. Each side may determine for itself the composition and structure of its strategic forces consistent with this limit.

Both the United States and Russia intend to reduce their strategic offensive forces to the lowest possible levels, consistent with their national security requirements and alliance obligations, reflecting the new nature of their strategic relationship. The United States considers operationally-deployed strategic nuclear warheads to be: re-entry vehicles on ICBMs in their launchers; re-entry vehicles on SLBMs in their launchers onboard submarines; and nuclear armaments located at heavy bomber bases. In addition, there will be some logistical spares stored at heavy bomber bases.

The five-Party START I agreement of 1991 continues in force unchanged, but is up for renewal in 2009. The START I comprehensive verification regime will provide the foundation for achieving confidence, transparency, and predictability in further strategic reductions. As noted in the Joint Declaration on the New Strategic Relationship, also issued in Moscow on 24 May 2003, additional supplementary measures, including transparency measures, may be agreed upon in the future.

The United States Senate ratified the Moscow Treaty in March 2003. The Russian Duma has yet to ratify the Treaty. back to chart