The New York Times

October 11, 1983

Build-Down (-Doom?)

By Herbert Scoville

Observers on both the right and the left have nodded approvingly toward President Reagan's ''build-down'' proposal for simultaneously reducing and modernizing our strategic forces. This is not surprising: Liberals and conservatives alike are drawn to the idea because it would allow the

procurement of new weapons while reducing the total numbers in the stockpile. People on both sides see it as a laudable compromise and do not notice that it totally fails to address the key goal of arms control -- to reduce the risk of the outbreak of a nuclear war. Nor, apparently, do they understand that it is President Reagan's latest attempt to subvert the arms control movement and buy Congressional support for the MX missile system. Even if build-down could be turned into a practical measure -- something its backers have failed to accomplish in its nine-month gestation

period -- it would not increase the stability of the strategic balance so long as no restrictions are placed on new multiple-warhead missiles such as the MX. It will only make it more likely that the MX and comparable Soviet missiles, such as the SS-18 and the new SS-X-24 -- all capable of carrying 10 warheads -- will be used in a first strike. The Congressional supporters of a build-down, such as Senators William S. Cohen and Sam Nunn and Representatives Les Aspin, Albert Gore Jr. and Norman D. Dicks, have pushed this concept on the Administration as their price for supporting procurement of the MX and as their justification to arms control constituents for doing so. They argue that their proposal will increase stability. In fact, together the MX and build-down would inevitably produce instability.

All one has to do is to put a few numbers into the build-down proposal and its emptiness becomes obvious. In order to make a build-down proposal attractive to arms controllers, its backers have tended to call for the destruction of two warheads for each new warhead added to the stockpile. In the interest of selling the proposal to arms controllers, the Administration avoided any specific ratio in its recent announcement. But unless this ratio is 2 to 1 or higher, the proposal will do little to reduce the number of weapons deployed. Why? The Administration is calling for the deployment of 100 MX missiles carrying 1,000 warheads. Using the 2 to 1 ratio and assuming that we will deploy 100 MX's, then 2,000 warheads would have to be withdrawn from the existing stockpile. This would require the removal of 550 Minuteman III's, each with three warheads, and 350 Minuteman II's and Titans, each with one warhead. The total number of land-based missiles or launchers in the United States strategic stockpile would be reduced from 1,050 to 250 -- a cut in potential Soviet targets by more than one-quarter. What this means, in effect, is that the United States will lose its relatively secure land-based force: The much

smaller remaining number of American missiles will continue to be housed in admittedly vulnerable Minutemen silos -- and would be a very attractive target for a Soviet pre-emptive attack. This is particularly true since a large fraction of the remaining missiles will carry warheads designed to have the accuracy and yield to threaten Soviet intercontinental ballistic missiles. Nor can the problem be solved by requiring a similar build-down on the part of the Soviet Union. Indeed, the threat to the United States' deterrent will be greatly magnified if Moscow chooses not to dismantle SS-18's with 10 warheads or to replace its older smaller missiles with SS-X-24's. Even if the Kremlin does not replace the older missiles but merely keeps its SS-18's and destroys some of its older missiles in order to reach the 5,000 warhead total or the 5 percent per year cut proposed by President Reagan, the United States' land-based missile force will be much more vulnerable than it is today. Of course, Soviet missiles will be similarly vulnerable, so the pressures to start a nuclear conflict will be even greater. There is no way of

getting around the basic fact of missile life that replacing missiles having one or only a few warheads by missiles with 10 warheads will lead to a more vulnerable and dangerous situation. Reductions that do not involve cutting the number of warheads per missile will lead to less stability -- no matter what kind of a Christmas package one wraps them in. Yet every single proposal that the Reagan Administration has put forward at the strategic arms reductions talks ignores this obvious fact. Unfortunately, the lesson is also lost on many Congressional enthusiasts eager to have their finger in some arms control pie, even if it means supporting the MX missile -- and thus increasing the chances of a nuclear war.

Herbert Scoville, formerly assistant director of the Arms Control and Disarmament Agency and Deputy Director of Central Intelligence, is president of the Arms Control Association.