960201 Fact Sheet: Treaty on the Further Reduction and Limitation of Strategic Offensive Arms (START II)  Return to: Index of "Arms Control, Counter-terrorism and Military Affairs || Electronic Research Collections Index || ERC Homepage


U.S. Department of State
96/02/01 Fact Sheet: Start II
Bureau of Public Affairs


                               FACT SHEET
           Treaty on the Further Reduction and Limitation
                 of Strategic Offensive Arms (START II) 
 
What is START II? 
 
The START II treaty is a bilateral treaty negotiated by the United 
States and Russia during 1991 and 1992.  It was signed by Presidents 
Bush and Yeltsin on January 3, 1993. 
 
START II builds on the foundation of START I to create an equitable and 
effectively verifiable agreement that reduces the number of strategic 
delivery vehicles (ballistic missiles and heavy bombers) and the number 
of warheads deployed on them.  Overall strategic forces will be reduced 
by 5,000 warheads in addition to the 9,000 warheads being reduced under 
START I. 
 
Key Provisions of START II 
 
Because START II builds upon the START I treaty, START I remains in 
effect.  START II will remain in force throughout the duration of START 
I, which has a 15-year duration and can be extended for successive 5-
year periods by agreement among the Parties to the treaty. 
 
START II sets equal ceilings on the number of strategic nuclear weapons 
that each Party may deploy.  The final ceilings will be reached in two 
phases.  Phase One is to be completed seven years after entry into force 
of the START I treaty (which was December 5, 1994).  Phase Two is to be 
completed by 2003.  However, Phase Two may be completed by the end of 
2000 if the United States is able to provide financial assistance for 
the elimination of strategic offensive arms in Russia. 
 
By the end of the first phase, each Party must have reduced the total 
number of its deployed strategic warheads to 3,800-4,250.  This includes 
warheads on deployed intercontinental ballistic missiles (ICBMs), 
warheads on submarine-launched ballistic missiles (SLBMs), and the 
warheads carried on heavy bombers with nuclear missions.  No more than 
1,200 warheads may be on deployed ICBMs with multiple reentry vehicles 
(MIRVs); no more than 2,160 on deployed SLBMs; and no more than 650 may 
be on deployed heavy ICBMs. 
 
By the end of the second and final phase, each Party must have reduced 
the total number of its deployed strategic warheads to 3,000-3,500.  Of 
those, none may be on MIRVed ICBMs, including heavy ICBMs.  No MIRVed 
ICBMs will be deployed by the end of the second phase.  No more than 
1,700-1,750 warheads may be on deployed SLBMs.  There will be no 
prohibition on MIRVed SLBMs. 
 
Downloading 
 
START II allows for a reduction in the number of warheads on certain 
existing MIRVed ballistic missiles.  This is called "downloading." Such 
downloading will be permitted in a carefully structured fashion, which 
is a slight variation from the rules agreed in START I. 
 
--  Each side will be able to download two existing types of ballistic 
missiles by up to four warheads each. 
 
--  No more than 105 ICBMs of one of those types may be downloaded by up 
to five warheads each.  Such an ICBM may only be deployed in silos in 
which it was deployed at the time the two START treaties were signed. 
 
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 may 
be downloaded to a single warhead, to comply with the requirement to 
eliminate all MIRVed ICBMs. 
 
The Russian SS-18 heavy ICBM and launchers for the SS-24 ICBM would be 
destroyed.  SS-24 ICBMs would 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 or, with the 
exception of SS-18 silos, by converting the launcher so that it is only 
capable of launching another type of missile.  Moreover, 154 SS-18 silos 
must be eliminated through destruction under START I. 
 
Under START II, those rules will continue to apply, but with the major 
exception of the SS-18.  Ninety SS-18 silos may be converted to launch a 
single-warhead ICBM, which Russia has said will be a variant of the SS-
25.  The START II treaty provisions specify conversion procedures which 
are subject to inspection and which are virtually irreversible without 
destroying the silo. 
 
In addition to the elimination or conversion of SS-18 silo launchers, 
all SS-18 ICBMs, whether deployed or non-deployed, must be eliminated no 
later than January 1, 2003.  This is a major improvement on START I, 
which did not require the destruction of silo-based missiles.  Moreover, 
this provision achieves the long-standing U.S.  goal of totally 
eliminating heavy ICBMs. 
 
Heavy Bombers 
 
Under START II, heavy bombers will be attributed as carrying the actual 
number of weapons--whether long-range air-launched cruise missiles 
(ALCMs), short-range missiles, or gravity bombs--for which they are 
equipped.  This number is specified in the treaty's Memorandum of 
Attribution and is subject to confirmation by a one-time exhibition of 
the bombers and by on-site inspections. 
 
This attribution formula is another improvement over START I.  Under 
START I, the first 150 U.S.  heavy bombers equipped to carry long-range 
ALCMs are attributed with 10 warheads; each bomber in excess of the 150 
would be attributed with the actual number of long-range ALCMs it is 
equipped to carry.  For the former Soviet Union, the first 150 heavy 
bombers are attributed with eight warheads; each heavy bomber in excess 
of 150 would be attributed with the number of long-range ALCMs it is 
equipped to carry.  For both Parties, all heavy bombers equipped to 
carry nuclear weapons other than long-range ALCMs are attributed with 
one warhead each. 
 
Up to 100 heavy bombers that were equipped for nuclear arms other than 
long-range ALCMs may be reoriented to a conventional role and exempted 
from accountability under START II.  Such bombers will be based 
separately from heavy bombers equipped to carry nuclear weapons, they 
will be used only for non-nuclear missions, and they must have 
observable features that differentiate them from nuclear-equipped heavy 
bombers of the same type.  If these heavy bombers are returned to a 
nuclear role, which is permitted, they will become accountable under 
START II and may not be returned to their exempted status. 
 
Verification 
 
The comprehensive, intrusive START I verification regime also will apply 
to START II.  Additionally, START II has new verification measures.  
These include the following: 
 
--  Observation of the conversion of SS-18 silos;  
 
--  Observation of SS-18 eliminations;  
 
--  Exhibitions of heavy bombers to allow confirmation of capacity; and 
 
--  Exhibition of reoriented bombers to confirm their observable 
differences. 
 
Moreover, reentry vehicle inspections (RVOSI) will allow inspectors 
visual access to the front ends of ICBMs and SLBMs to verify that the 
numbers of warheads attributed to those systems match the number 
deployed on them.  

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