START 1 – Strategic Arms Reduction Treaty 1 – Signed Between US and USSR on Nuclear Warheads – Ensuring the Peace

START 1 – Strategic Arms Reduction Treaty was a bilateral treaty between the United States of America and the Union of Soviet Socialist Republics (USSR) on the reduction and limitation of strategic arms.


Strategic Arms Reduction Treaty was signed on July 31, 1991 and entered into the force on December 5, 1994. The Duration of the treaty is about 15 years with option to extend for unlimited five year period. The treaty was expired on December 5, 2009. The parties involved in this treaty are United States, Russian Federation, Belarus, Kazakhstan and Ukraine.


The U.S.-Soviet Strategic Arms Reduction Treaty, known as START I, was signed 31 July 1991 by U.S. President George H.W. Bush and Soviet President Mikhail Gorbachev.

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 the 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elements of START I — first and foremost the limits on the number of warheads and delivery vehicles — quickly became outdated, its verification and transparency provisions maintained their value until the treaty’s last days.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 proved to be excessively complicated, cumbersome and expensive to continue, which eventually led the United States and Russia to replace it with a new treaty in 2010.

Negotiations that led to the signing of START I began in May 1982. In November 1983, the Soviet Union “discontinued” talks after the United States began deploying 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 that encompassed strategic weapons, intermediate-range forces and missile defense. These talks received a significant boost at the Reykjavik summit between Presidents Ronald Reagan and Mikhail Gorbachev. In December 1987, the Intermediate Range Nuclear Forces Treaty was signed. Negotiations subsequently turned to the reduction of strategic weapons.

START I entered into force on December 5, 1994. The break-up of the Soviet Union in December 1991 and the need to make arrangements with regard to its nuclear inheritance contributed to a three-year delay between the signing of the treaty and its entry into force. Principles for adapting START I to new political realities 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 Russia was designated a nuclear weapon state, while the other three assumed an obligation to join the NPT as non-nuclear states and eliminate all START I accountable weapons and associated facilities within 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 experienced intense domestic debates over how to deal with its nuclear inheritance that dragged on for more than two years; 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 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. Parties were then obligated to maintain those limits during the next eight years. In fact, both the United States and Russia continued reductions after reaching START I mandated limits. By the time of the treaty’s expiration, their strategic nuclear arsenals were significantly below those stipulated in the treaty.

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 treaty never entered into force due to what Russia perceived as serious deficiencies of that treaty. Consultations on another treaty, sometimes referred to as START III, were conducted from 1997-2000 but ended without result. The Moscow Treaty provided for significantly lower limits on strategic weapons, but lacked verification and transparency provisions.

START I remained in force until December 5, 2009. It contained the option of extending the treaty for five-year periods, but Washington and Moscow decided against extension — negotiations were already underway on a new, replacement treaty, and START I was allowed to expire.

Treaty Obligations

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 sub-limits: 4,900 warheads for ICBMs (land-based intercontinental ballistic missiles) and SLBMs (submarine launched ballistic missiles), 154 heavy ICBMs (defined as having a launch weight greater than 106t or a throw-weight greater than 4,350kg), 1,540 warheads for these heavy ICBMs (Only the Soviet Union possessed this type of missile), 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.

The construction of new types of heavy ICBMs and SLBMs is banned, although modernization programs and, in exceptional cases, new silo construction, are permitted.

The treaty bans the testing of missiles equipped with a greater number of warheads than established in the treaty, and bans any new ballistic missiles with more than 10 warheads. Parties to the treaty may also reduce the number of warheads attributed to a specific missile. However, no more than three existing missile types may have the number of warheads reduced, and the total reduction may not exceed 1,250 warheads.

While the treaty counts each ICBM and SLBM reentry vehicle as a single warhead, counting rules for warheads attributed to heavy bombers are more complicated. Each Russian heavy bomber equipped to carry long-range nuclear ALCMs (defined as having maximum range of 600km or more), up to a total of 180 bombers, counts as eight warheads toward the 6,000 warhead limit, even though existing Russian heavy bomber types can carry between six and 16 ALCMs. Each Russian heavy bomber above the level of 180 has its actual number of ALCMs counted toward the 6,000 warhead limit. Similarly, each U.S. long-range nuclear ALCM-carrying heavy bomber, up to a total of 150 bombers, counts as 10 warheads toward the 6,000 warhead limit, and each bomber in excess of 150 has the actual number of ALCMs it can carry counted toward the warhead limit. Bombers not equipped to carry long-range nuclear ALCMs are counted as one warhead.

Verification and Compliance

START I contains extensive provisions for verification. These include:

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

2. Data exchange: Accompanying the START I treaty is a Memorandum of Understanding drafted by the two parties, which contains an extensive set of data, including 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 is required to provide notification about any change in that data shortly after it occurs. In addition, parties must exchange 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 are short-notice (baseline data, data update, reentry vehicle, etc.) while others are “planned” (verification of technical data, the right to observe elimination of missiles and facilities, etc.). The treaty also provides for a special verification regime for mobile ICBMs. During the first seven years (the period of reductions), the United States conducted 335 inspections; Russia conducted 243.

4. Perimeter and portal monitoring of plants that produce mobile ICBMs. Because 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.

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *