global issues

Nuclear and Other Weapons Issues

Treaties: A Chronology

"No treaty, however much it may be to the advantage of all, however tightly it may be worded, can provide absolute security against the risks of deception and evasion. But it can, if it is sufficiently effective in its enforcement and if it is sufficiently in the interests of its signers, offer far more security and far fewer risks than an unabated, uncontrolled, unpredictable arms race." (U.S. President John F. Kennedy, calling for support for a comprehensive nuclear test ban treaty, June 10, 1963)

Since the 1960s, the U.S. has adopted and ratified a series of bilateral and multilateral treaties aimed at nuclear disarmament and nonproliferation. The U.S. also has opted not to ratify specific treaties (Comprehensive Test Ban Treaty, or CTBT) or abrogated its participation in treaties such as the Anti-Ballistic Missile (ABM) Treaty. The Bush Administration's withdrawal from the ABM treaty in 2002 was the first time a major power has withdrawn from a nuclear treaty after it had become legally binding.

The following chronicles the most significant international nuclear weapons treaties and their current status in terms of adoption, ratification, and implementation.

Partial Test Ban Treaty (PTBT)

Signed by the U.S., former Soviet Union and United Kingdom and ratified by President John F. Kennedy in 1963, the Partial Test Ban Treaty prohibits nuclear testing in outer space, in the atmosphere, and underwater. This treaty, which took nearly eight years to complete, is still in effect today.

Nuclear Nonproliferation Treaty (NPT)

The NPT – also known as the Nuclear Nonproliferation Treaty – was opened for signature in 1968 and entered into force in 1970. This landmark treaty is intended to prevent the spread of nuclear weapons and weapons technology, promote nuclear disarmament, and promote peaceful uses of nuclear energy. More countries have ratified the NPT than any other arms control and disarmament agreement in history. (Cuba, India, Israel and Pakistan have not joined the treaty. North Korea withdrew from the NPT in April 2003.) The NPT is considered to be the cornerstone of global efforts to meet the challenge of international peace and security.

During the 2000 NPT Review Conference, the countries of Brazil, Egypt, Ireland, Mexico, New Zealand, South Africa and Sweden formed the New Agenda Coalition in order to "bridge the differences and address frustrations with the shortcomings of nuclear-weapon states to live up to their commitments."

In May 2005, the States Parties to the NPT met in New York – for the seventh time since its entry into force in 1970 – to review implementation and compliance with the Treaty, and to identify further areas for progress. According to the Arms Control Association, the 2005 NPT Review Conference in New York came to a close "failing to produce agreement on any substantive reports or statements." It represented one of the "most acute failures in history of the NPT" with none of the three "main committees" reaching agreement on key treaty issues such as disarmament, nonproliferation and regional security, and peaceful uses of nuclear energy under strict and verifiable control.

Anti-Ballistic Missile (ABM) Treaty and SALT Treaties

The ABM Treaty between the U.S. and the former Soviet Union was signed, ratified and entered into force in 1972, as a result of SALT I (Strategic Arms Limitation Talks.) The ABM Treaty's fundamental purpose was to prevent deployment of territory-wide defenses against strategic ballistic missiles. Specifically, this treaty stated that the U.S. and Soviet Union could only have two ABM deployment areas located in such a way as to constrain a nationwide ABM defense or prevent the development of one. In 1976, the treaty was amended to reduce the number of ABM deployment areas from two to one. Furthermore, once a country deployed a defensive system at a given location, it could not deploy at any other location, even if it closed the original site. In the 1970s, the Soviet Union established its one ABM facility in Moscow, which continues to operate today. The U.S. established its site in Grand Forks, North Dakota, but closed it in 1976, just a few months after the system became operational.

In 1979, President Jimmy Carter negotiated the SALT II Treaty. It called for limiting the number of delivery vehicles (launchers and bombers) to 2,400 on each side, to be reduced to 2,250 by the end of 1981. The SALT II Treaty was never considered or ratified by Congress due to the Soviet invasion of Afghanistan. In 1986, President Ronald Reagan declared that the U.S. would no longer be bound by the SALT II limits due to Soviet violations of its arms control commitments.

During the 1980s and 1990s, various presidential administrations broadened the interpretation of the ABM Treaty and also attempted to amend its components. In 2002, under the leadership of current President George W. Bush, the U.S. unilaterally broke away from the treaty in order to pursue a missile defense program. While there are divergent opinions among arms control experts, it is believed by many that the result of such abrogation will make America less secure, not more.


In an effort to urge Russia to reduce the deployment of strategic arms and support nonproliferation, the U.S. negotiated and signed two treaties in the 1990s. First, the Strategic Arms Reduction (START) I Treaty was signed in 1991, with the U.S. and Russia committing to serious reductions in nuclear weapons, both strategic warheads as well as long-range delivery systems (missiles, submarines, and bombers.) Under START I, the U.S. reduced its deployed nuclear arsenal from the 1990 level of about 13,000 warheads to 6,000. Russia has reduced the number of its warheads from 11,000 to 6,000.


In 1996, the U.S. and Russia agreed to further reduce deployed strategic forces to fewer than 3,500 intercontinental warheads by signing the START II Treaty. This treaty also banned the deployment of land-based missiles with more than one warhead. START II essentially set "ceilings" on the number of strategic nuclear weapons either side can deploy, and implemented those ceilings in two phases: Phase One, to be completed by 1991; and Phase Two, to be completed by 2003. In 1997, the U.S. and Russia agreed to extend the time periods for completion of Phase One until December 31, 2004, and Phase Two until December 31, 2007. The Russian Duma ratified the treaty, its extension protocol and the concurrently negotiated ABM treaty succession agreements in 2000, contingent on U.S. ratification of both the extension protocol and the ABM treaty succession agreements. The U.S. Senate has not ratified the extension protocol as required by the Duma's ratification in order for the treaty to be in force. Given the Bush Administration's decision to abandon the ABM treaty, it appears that the START II treaty is moot.

Comprehensive Test Ban Treaty

The CTBT, a multilateral treaty completely banning all nuclear explosions whether for weapons or peaceful purposes, was concluded in 1996 after 40 years of bipartisan effort. The U.S. was the first to sign. President Clinton called it "the longest-sought, hardest-fought prize in the history of arms control" and established a moratorium on testing. On October 13, 1999, the U.S. Senate rejected the opinion of the Joint Chiefs of Staff, former Chairman of the Joint Chiefs of Staff, numerous nuclear weapons and verification experts, as well as a large majority of the American people, when it voted down ratification of the CTBT. After only three days of debate, the Senate voted along party lines in rejecting the Treaty.

Although 173 countries have signed the Treaty and 96 have ratified it, including Britain, France, and Russia, Article XIV of the CTBT requires that 44 nuclear capable states must ratify before the Treaty enters into force. There are 11 states on that list that still must ratify, including the U.S., China, North Korea, India, and Pakistan, in order for the treaty to be legally binding. Because President Bush has not withdrawn the CTBT from the Senate, the U.S. signature on the treaty is considered an expression of support, even though his administration is opposed to the CTBT. Unless the U.S. formally withdraws from the CTBT, while not legally bound, the U.S. is politically restricted from the resumption of nuclear testing.

Strategic Offensive Reductions Treaty (SORT)

The Bush Administration has sought to bypass START II by establishing a new "strategic framework" with Russia. Under this framework, both countries would reduce deployed strategic warheads, but President Bush hoped to accomplish this without a formal treaty. While Russia supported the deployment levels, it requested a treaty to formalize them. Therefore, in May 2002, President Bush and Russian President Vladimir Putin signed the Strategic Offensive Reductions Treaty, also known as the SORT or Moscow Treaty. It is intended to reduce the numbers of U.S. and Russian deployed nuclear warheads to between 1,700 and 2,200 by December 31, 2012. The treaty further establishes a Bilateral Implementation Commission, to meet twice annually in order to establish verification and reduction procedures. START I remains in effect and unchanged under this treaty.

The SORT does not require the actual destruction of nuclear warheads, nor does it spell out where warheads should be located after they are removed from launchers. The Treaty also expires the same day that the deployed warheads must reach agreed-upon levels. This would make warhead reactivation on short notice relatively easy. Given the high risk of security failures in Russia, stored warheads are likely to fall into the hands of rogue states or terrorists. Further, the treaty does not insist on a schedule for reductions nor does it provide any plan for verification and compliance, therefore providing no predictability or transparency for either the U.S. or Russia.

In June 2002, President Bush sent the SORT to the Senate for consideration. It was heard in the Senate Foreign Relations Committee and the Senate Armed Services Committee in February 2003. To help remedy the treaty's shortcomings, the Senate Foreign Relations Committee added two conditions to the agreement. One mandates an annual report by the administration on U.S.-Russian Cooperative Threat Reduction programs. The other requires an annual update on the status of U.S. and Russian treaty implementation, including strategic force levels, planned reductions each calendar year, and verification or transparency measures that have been or might be employed.

In May 2003, the U.S. Senate ratified the SORT by a vote of 95-0, thus approving the two conditions offered by the Senate Foreign Relations Committee in February. In May 2003, the Russian Duma – the lower house of Russia's parliament – ratified the treaty on a 294-134 vote. Later that same month, Russia's upper house of parliament ratified the SORT by a 140-5 vote, giving the treaty its final seal of approval.

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