The Purpose of START II
The principal U.S. objective in strategic arms control is to increase stability at significantly lower levels of nuclear weapons. START II is an equitable and effectively verifiable agreement that reduces the number of strategic nuclear delivery vehicles and the warheads on them. Overall strategic nuclear forces will be reduced by an additional 5,000 warheads beyond the 9,000 warheads being reduced under START I.
The START II Parties
The START II Treaty was negotiatied by the United States and Russia between 1991 and 1992 and submitted to the Senate by President George Bush following signature on January 3, 1993.
START II's Central Features
The START II Treaty builds upon the START I Treaty signed on July 31, 1991 between the United States and the Soviet Union. All START I provisions will pertain, except as explicitly modified in the new Treaty. It will remain in force throughout the duration of START I (START I has a 15-year duration and can be extended for successive 5-year periods by agreement among the Parties).
The Treaty will set equal ceilings on the number of strategic nuclear weapons that can be deployed by either side. Ceilings will be set for two phases: Phase One to be completed seven years after entry into force of the START I Treaty (START I entered into force on December 5, 1994); and Phase Two to be completed by the year 2003. Phase Two may be completed by the end of the year 2000 if the United States can help finance the elimination of strategic offensive arms in Russia.
The Treaty will set ranges for some of the central limits:
Downloading
The Treaty will allow for a reduction in the number of warheads on certain ballistic missiles. Such "downloading" will be permitted in a carefully structured fashion, modifying the rules agreed in START I:
Thus, the three-warhead U.S. Minuteman III ICBM, the four-warhead Russian SS-17 ICBM and 105 of the six-warhead Russian SS-19 ICBMs will be able to be downloaded to a single warhead, to comply with the requirement to eliminate all MIRVed ICBMs. The U.S. Peacekeeper ICBM and the Russian SS-18 heavy ICBM and SS-24 ICBMs must all be eliminated, in accordance with START procedures.
Missile System Elimination
In START I, deployed SLBMs and most deployed ICBMs may be removed from accountability either by destroying their launchers (silos for fixed ICBMs, mobile launchers for mobile ICBMs, and launcher sections of submarines for SLBMs), or by converting those launchers so that they can only carry another type of permitted missile. The one exception is the SS-18; under START I, the requirement to eliminate 154 deployed SS-18s must be met through silo destruction, not conversion.
Under START II, those rules generally will continue to apply. The major exception will again be the SS-18. Ninety SS-18 silos may be converted to carry a single-warhead missile, which Russia has said will be an SS-25-type. The Treaty will lay out specific procedures, including on-site inspections, to ensure that those converted silos will never again be able to launch a heavy ICBM. The remaining 64 SS-18 silos subject to this Treaty will have to be destroyed.
In exchange for the right to retain up to 90 converted SS-18 silos, the Treaty will require that all SS-18 missiles and canisters, both deployed and non-deployed, be eliminated no later than January 1, 2003. This is a major change from the START I Treaty. Generally, START I did not seek destruction of missiles. But in START II, the Russians have agreed to eliminate all SS-18 missiles, both deployed and non-deployed. This fully achieves a long-standing U.S. goal, the complete elimination of heavy ICBMs.
Heavy Bombers
In START I, nuclear heavy bombers are subject to more flexible counting rules than are ballistic missiles. Each heavy bomber equipped to carry only short-range missiles or gravity bombs counts as one warhead. U.S. heavy bombers equipped to carry long-range nuclear air-launched cruise missiles (ALCMs) each count as 10 warheads, and Soviet heavy bombers equipped to carry long-range nuclear ALCMs each count as eight warheads.
In START II, heavy bombers will be counted using the number of nuclear weapons -- whether long-range nuclear ALCMs, short-range missiles or gravity bombs -- for which they are actually equipped. This number will be specified in the Treaty Memorandum on Attribution and will be confirmed by a one-time exhibition and by routine START on-site inspections.
Another new feature of this Treaty will be the provision that up to 100 heavy bombers that have never been accountable under the START I Treaty as long-range-nuclear-ALCM heavy bombers may be reoriented to a conventional role. Such bombers will not count against the Treaty warhead limits. They will be based separately from heavy bombers equipped for heavy weapons, will be used only for non-nuclear missions, and will have observable differences from other heavy bombers of the same type that are not reoriented to a conventional role. Such heavy bombers may be returned to a nuclear role after three months notification, but then may not be reoriented again to a conventional role.
Verification
The comprehensive START I verification regime will continue to apply to the new Treaty. In addition, START II will include some new verification measures, such as observation of SS-18 silo conversion and missile elimination procedures, exhibitions and inspections of all heavy bombers to confirm weapon loads, and exhibitions of heavy bombers reoriented to a conventional role to confirm their observable differences.