Center for Arms Control and Non-Proliferation

Counting Rules Under START and Treaty of Moscow (SORT)

by John Isaacs [contact information]

March 10, 2009

START COUNTING RULES

Deployed strategic delivery vehicles and accountable warheads (number based on the capacity of the delivery systems).

The ceilings are:

• 1,600 delivery vehicles: deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers for each side

• 6,000 "accountable" warheads on ICBMs, SLBMs, and heavy bombers, of which no more than 4,900 may be on ICBMs and SLBMs, 1,540 on heavy missiles (the Russian SS-18), and 1,100 on mobile ICBMs

• Ballistic missile throw-weight (lifting power) is limited to 3,600 metric tons on each side

Specifically:

• Heavy bombers equipped only with bombs or short-range attack missiles (SRAMs) are counted as carrying one warhead each

• U.S. heavy bombers may carry no more than 20 long-range air-launched cruise missiles (ALCMs) each. The first 150 of these bombers count as carrying only 10 ALCMs each

• Russian heavy bombers may carry no more than 16 ALCMs each. The first 180 of these bombers count as carrying only eight ALCMs each

• No more than 1,250 warheads may be "downloaded" (removed from) and not counted on existing multiple-warhead ballistic missiles

Under the terms of the START I treaty the main unit of account is the launcher: the missile silo, mobile launcher, or bomber. Even after a missile is removed from the silo, that silo still counts as a launcher for the type of missile for which it was designed, and is included in the MOU data. For START I purposes both the missile and the warheads it carries will continue to be counted until the silo is destroyed, the destroyed silo has been inspected, and a 90 day period has elapsed. (See “Russia: START I Counting Rules,” Nuclear Threat Initiative, February 1999).

PROBLEM: “The U.S. now counts 5,951 units under the “warheads” category of the START; applying the SORT understanding, however, there would be only 2,900 units to be counted in that section.” (Edward Ifft, “Controlling Nuclear Weapons: Priorities for the Obama Administration,” Lecture at Georgetown University, January 22, 2008).

Expires December 5, 2009

TREATY OF MOSCOW (SORT) COUNTING RULES

Deployed, strategic weapons only

The ceilings are:

• 1,700 to 2,200 deployed strategic warheads

Unlike past strategic arms control agreements between Moscow and Washington, SORT does not specify which warheads are to be reduced or how reductions should be made. (See "Strategic Offensive Reduction Treaty at a Glance,” Arms Control Today, September 2006).

There are differing interpretations of SORT commitments:

• The United States counts the number of warheads on its “operationally deployed” intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs), as well as warheads loaded on heavy bombers or stationed at heavy bomber bases. Some spare strategic warheads stored at heavy bomber bases, however, are not counted against the treaty limit.

• Russia has not publicly stated what warheads it considers limited by the treaty.

PROBLEM: “The U.S. wants to put conventional warheads on ICBMs and SLBMs [Prompt Global Strike] – Russia wants to count those as nuclear weapons.” (Edward Ifft, “Controlling Nuclear Weapons: Priorities for the Obama Administration,” Lecture at Georgetown University, January 22, 2008).

Expires December 31, 2012