START I Russian Treaty

Treaty Status

START I Treaty
Signed: 31 July 1991
Ratified by the Russian Federation: 4 November 1992
Entered into force: 5 December 1994

Lisbon Protocol: Signed 23 May 1992

Treaty Summary

The U.S.-Soviet Strategic Arms Reduction Treaty, known as START I, was signed on July 31, 1991 by U.S. President George H.W. Bush and Soviet President Mikhail Gorbachev. It is probably the longest treaty in history and consists of the treaty itself, the Memorandum of Understanding, which contains data about strategic nuclear forces of the parties, several Protocols (Inspections, Conversion and Elimination, Notifications, etc.), Definitions Annex, as well as a host of agreements, joint statements, letters, and other documents.

Negotiations that led to the signing of START I began in May 1982. In November 1983 the Soviet Union "discontinued" the talks after the United States began to deploy intermediate-range missiles in Europe. In January 1985 U.S. Secretary of State George Schultz and Soviet Foreign Minister Andrey Gromyko agreed on a new formula for three-part negotiations, which encompasses strategic weapons, intermediate-range forces, and missile defense. A significant impulse to these talks was given at the Reykjavik summit between Presidents Ronald Reagan and Mikhail Gorbachev. In December 1987 the INF Treaty was signed and negotiations concentrated on the reduction of strategic weapons.

START I had a duration of 15 years. Reductions mandated by the treaty were to be completed no later than seven years after its entry into force and during the subsequent eight years parties were obligated to maintain those limits. In fact, both the United States and Russia continued reductions after reaching START I mandated limits and by the time of the treaty's expiration their strategic nuclear arsenals were significantly below those stipulated in the treaty.

START I entered into force on December 5, 1994. The delay was caused by the breakup of the Soviet Union in December 1991 and the need to make arrangements with regard to its nuclear inheritance, including participation in international treaties. Principles of the solution on START I were agreed upon in May 1992 in the Lisbon Protocol — according to that agreement, four post-Soviet states, Russia, Belarus, Kazakhstan, and Ukraine, were recognized as parties to START I in place of the Soviet Union, but only one of them, Russia, was a nuclear weapon state while the other three took an obligation to join the NPT as non-nuclear states and eliminate all START I accountable weapons and associated facilities in seven years (the period of reductions mandated by the treaty). Whereas Belarus and Kazakhstan quickly joined the NPT and ratified START I "as is," Ukraine saw intense domestic debates that lasted more than two years and its first START I ratification resolution was rejected by the United States and Russia.

Although the entry into force of START I took more than three years, some important activities were conducted shortly after its signing, most notably exchange of data on strategic weapons and associated facilities, as well as inspections to verify data on technical characteristics of strategic missiles and implementation of provisions on test launches and telemetry exchanges.

START I remained in force until December 5, 2009. It allowed the parties an option of extending it for five-year periods, but Washington and Moscow decided against using that option and allowed the treaty to expire as negotiations were underway on a new, replacement treaty.

START I established an aggregate limit of 1,600 delivery vehicles and 6,000 warheads for each party (a reduction from 10-12,000 warheads in 1991). Within that limit, the Treaty established three sublimits: 4,900 warheads for ICBMs (land-based intercontinental ballistic missiles) and SLBMs (submarine-launched ballistic missiles), 1,540 warheads for heavy ICBMs and 154 ICBM missiles (the limit applied only to the Soviet Union because the United States does not have ICBMs), and 1,100 warheads for mobile ICBMs (de facto applied only to the Soviet Union and Russia because the United States, shortly after the signing of START I, decided to forego deployment of such missiles). The Treaty also established a limit of 3,600 metric tons (t) for the throw-weight of ballistic missiles.

Although START I reductions were calculated in warheads, it did not address them directly: the 6,000 aggregate limit and sublimits was calculated according to special accounting rules. Each ballistic missile was attributed with an agreed number of warheads (usually the maximum number with which each type of ballistic missiles had been tested). Each party was also allowed to reduce that agreed number (download ballistic missiles) so that the number of downloaded warheads did not exceed 1,250. Number of ballistic missile warheads were subject to verification through special inspections.

The accounting rules for heavy bombers were more complicated: each heavy bomber equipped with gravity bombs counted as only one warhead against the 6,000 limit; each U.S. heavy bomber equipped with nuclear ALCMs (long-range air-launched cruise missiles) was allowed to carry up to 20 such weapons, but counted as only 10 warheads against the 6,000 limit; each Soviet heavy bomber equipped with nuclear ALCMs was allowed to carry 16 such weapons, but counted as only 8 warheads against the 6,000 limit; these rules applied only to the first 150 heavy bombers, all heavy bombers above that number were supposed to be counted with the maximum allowed number of ALCMs. Heavy bombers carrying conventional weapons did not count against the 6,000 limit at all.

START I also established certain limits on the modernization of strategic delivery vehicles. Most significant among them was a ban on increasing the number of warheads on existing types of ballistic missiles and a ban on new types of heavy ICBMs and SLBMs.

START I contained extensive provisions for verification. These included:

1. National Technical Means (NTMs) together with a ban on actions that impaired the effectiveness of NTMs of the other party;

2. Data exchange: an extensive set of data contained in the Memorandum of Understanding included numbers and locations of all strategic delivery vehicles, both deployed and non-deployed as well the locations and diagrams of all facilities associated with strategic delivery vehicles, such as bases, storage and production facilities, etc. Each party was required to provide notification about any change in that data shortly after it occurred and, in addition, parties exchanged the entire set of data contained in the Memorandum every six months;

3. On-site inspections to verify the accuracy of data contained in the Memorandum of Understanding. Some of those inspections were short-notice (baseline data, data update, reentry vehicle, etc.) while others were "planned" (verification of technical data, the right to observe elimination of missiles and facilities, etc.). The treaty also provided for a special verification regime for mobile ICBMs. During the first seven years (the period of reductions) the United States conducted 335 inspections while Russia 243 inspections;

4. Perimeter and portal monitoring of plants that produce mobile ICBMs. Since the United States decided not to deploy such missiles, this measure only applies to Russia: the United States established monitoring at the Votkinsk plant (or, rather, continued, because its monitoring began under the INF Treaty);

5. A ban on encryption of telemetry transmitted from ballistic missiles during test launches and exchange of all such telemetry;

6. A set of confidence-building measures.

During the 1990s, the United States and Russia undertook several attempts to replace START I with a new treaty that would have provided for deeper reductions. The 1993 START II never entered into force due to what Russia perceived as serious deficiencies of that treaty. Consultations on another treaty, sometimes known as START III, in 1997-2000 ended without result. The 2002 Moscow Treaty provided for significantly lower limits on strategic weapons, but lacked the verification and transparency provisions.

START I was the first treaty to provide for deep reductions of U.S. and Soviet/Russian strategic nuclear weapons. It played an indispensable role in ensuring predictability and stability of the strategic balance and serving as a framework for even deeper reductions. Even though many elements of START I – first and foremost the limits on the number of warheads and delivery vehicles – quickly became outdated, its verification and transparency provisions maintained their value until the treaty's last days. At the same time, START I (the main elements of which were negotiated in the final years of the Cold War), proved to be excessively complicated, cumbersome, and expensive to continue, which is why the United States and Russia eventually decided to replace it with a new treaty.