Center for Arms Control and Non-Proliferation

New START Won’t Require Cuts in U.S. Force Structure

by Kingston Reif [contact information]

October 16, 2009

At their July summit meeting in Moscow, President Obama and President Medvedev agreed that the START follow-on agreement will limit each side to no more than 1,500 to 1,675 warheads on no more than 500 to 1,100 strategic nuclear delivery vehicles. Republicans have latched onto the lower bound of the delivery vehicle limit, arguing that the United States will be forced to eliminate essential nuclear and conventional systems in order to get down to 500.

That is not quite accurate. The range for delivery vehicles contained in the Joint Understanding is best viewed as the opening positions of the two countries. While we probably can’t go all the way down to 500 delivery vehicles, at least during this round, we should be able to go well below the upper bound of the proposed 500 to 1,100 limit without making any significant changes to our current force structure. Here’s how.

According to the latest START data exchange, the United States has 5,916 warheads attributed to 1,188 delivery vehicles. In reality, the United States “actually” deploys approximately 2,200 warheads on approximately 850 delivery vehicles.

This discrepancy is attributable in part to the fact that while the United States has converted its B-1 bomber force and four (out of 18) Trident submarines to conventional-only roles, they still count against the START I limits because the Treaty counts force levels based on the total number of warheads each delivery vehicle could carry, not on how many warheads the vehicles actually do carry. For example, though the converted submarines no longer carry nuclear-armed SLBMs, they still count under START I.

In order for these and other systems that no longer have a nuclear role not to count under the START follow-on limits, the United States will have to reassure Russia that they will not be refitted with nuclear warheads and Russia will have to agree to looser counting and elimination rules. This shouldn’t be too heavy of a lift. As the Brookings Institution’s Steven Pifer notes, START II, which was signed in 1993 but never entered into force, already provides a way to deal with conventional bombers. The United States and Russia should also be able to agree to measures that allow Moscow to verify that the converted Trident subs do not contain nuclear-armed SLBMs and could not be refitted with them quickly.

Though more complicated, U.S. plans for a conventional prompt global strike capability should also be able to be accommodated in the follow-on agreement. Given the difficulties associated with distinguishing between a nuclear and a conventional payload, Russia is likely to insist that strategic systems be counted whether they carry nuclear or conventional warheads. According to Pifer, “It would be far more straightforward to treat all warheads on ICBMs and SLBMs as nuclear and thus limited under the new treaty. As long as the number of conventional warheads is relatively small and the overall warhead limit is in the range of 1,500 to 1,675, this should have minimal impact on the U.S. strategic nuclear force.”

The bottom line is that assuming the United States and Russia can agree to new elimination, counting, and inspection rules, which should be doable, the United States can live with a delivery vehicle limit of around 800, which comports with the number of nuclear-armed systems it actually deploys and would not require it to eliminate bombers, missiles, and submarines that have been converted to conventional roles (since they would not count against the limit under the new counting rules) or prevent it from deploying a limited prompt global strike capability.

Imagine that: After a sustained and at times difficult dialogue, the two sides to a negotiation agree to an end result that is somewhere in the middle of their respective opening positions. The United States could probably go even lower if it deactivated some of the 24 missile tubes on each of its ballistic missile submarines, although that might be a bridge too far for this round of negotiations.

Of course, all of these issues will become much more difficult as the United States and Russia begin to entertain reductions below the limits outlined in the Joint Understanding. But for now, the goals are to 1) ensure that limits and verification measures are placed on the two largest nuclear arsenals on the planet and 2) make an initial, modest down payment on even deeper nuclear reductions in the future.