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Some members of the Congress have expressed concern that the recent Administration decision to renounce its "no-undercut" policy regarding the SALT II arms control treaty could fuel an escalation in the arms race. There is great uncertainty about the potential effects, if any, of forgoing SALT. As requested by the House Committee on Armed Services, this preliminary analysis examines the probable bounds, analyzing the effects of both countries continuing with SALT-type restraints, and those of a possible robust expansion of Soviet forces. The report then examines the effects of such changes on the survivability of U.S. forces--particularly land-based forces. In accordance with the Congressional Budget Office (CBO) mandate to provide objective analysis, this report contains no recommendations.

Bonita J. Dombey of CBO's National Security Division prepared the study, under the general supervision of Robert F. Hale and John D. Mayer, Jr. M. Diane Griffith supplied the cost analysis. Bertram D. Braun assisted extensively throughout the study's preparation. Alan Zukerman also provided assistance. Patricia H. Johnston edited the manuscript. G. William Darr prepared the report.
 

Rudolph G. Penner
Director
August 1986
 
 

INTRODUCTION AND SUMMARY

SECTION I. TODAY'S BALANCE OF FORCES

• Measures Used in This Analysis
• Today's Balance

SECTION II. PROJECTIONS UNDER SALT-TYPE CONSTRAINTS

• Defining SALT-Type Constraints
• Projections

SECTION III. PROJECTIONS WITHOUT SALT-TYPE CONSTRAINTS

• Soviet Expansion Without Arms Control Limits
• U.S. Responses

SECTION IV. SURVIVABILITY OF U.S. FORCES WITH AND WITHOUT ARMS CONTROL LIMITS

• Implications for the SICBM
• Effects on Other Land-Based Missiles
• Synergism

APPENDIX A. ILLUSTRATIVE SOVIET BALLISTIC MISSILE FORCES WITH SALT-TYPE CONSTRAINTS AND WITH ROBUST EXPANSION

APPENDIX B. ASSUMPTIONS UNDERLYING SOVIET FORCES USED TO ATTACK THE SICBM SYSTEM
 

TABLE 1.	ADDED LIFE-CYCLE COSTS TO MAINTAIN AT LEAST 250 SURVIVING SICBMs UNDER THREE ALTERNATIVES
TABLE A-l.	ILLUSTRATIVE SOVIET BALLISTIC MISSILE FORCES WITH SALT-TYPE CONSTRAINTS
TABLE A-2.	ILLUSTRATIVE SOVIET BALLISTIC MISSILE FORCES WITH ROBUST EXPANSION
FIGURE 1.	CURRENT U.S. AND SOVIET STRATEGIC FORCES
FIGURE 2.	U.S. AND SOVIET STRATEGIC FORCES (With SALT-Type Constraints)
FIGURE 3.	RANGE OF POSSIBLE SOVIET STRATEGIC FORCES BY 1996 (Without Arms Control Limits)
FIGURE 4.	U.S. AND SOVIET STRATEGIC FORCES, 1990 and 1996 (Without Arms Control Limits)
FIGURE 5.	SICBM SURVIVABILITY (Baseline Force: With SALT-Type Constraints Versus Expanded Soviet Force)
FIGURE 6.	SURVIVABILITY OF U.S. SMALL ICBM, 1986, 1990, AND 1996 (Soviet Forces Unconstrained by Arms Control Limits)
FIGURE 7.	SOVIET WARHEADS NEEDED TO DESTROY 50 PERCENT AND 90 PERCENT OF U.S. BASELINE SICBM FORCE, AS A FUNCTION OF DISPERSAL AREA

 
 

In 1979, the United States and the Soviet Union signed the SALT II treaty to control the number of strategic nuclear weapons that each country could have.¹ The treaty placed limits both on the number of launchers carrying multiple warhead missiles and on the total number of launchers. The last of the treaty's provisions expired in December 1985.

Since the treaty was not approved by the U.S. Senate, its terms never became binding U.S. policy. Instead, until recently, the Administration pledged not to "undercut" the provisions of the treaty so long as the Soviets followed the same policy. In June 1986, however, President Reagan announced that the United States would no longer be bound by the provisions of SALT II, arguing that the Soviet Union had violated its provisions. The Administration is negotiating with the Soviet Union on other strategic nuclear arms control proposals, including one recently made by the Soviets.

Some Members of the Congress have expressed concern about the U.S. decision to renounce the "no-undercut" policy. Indeed, a recent nonbinding resolution of the House called on the Administration to continue not to undercut SALT II. Concerns are based in part on the possibility that the absence of SALT II restraints could fuel an escalation in the arms race.

Would the absence of arms control limits speed up the arms race? It need not, of course. Both sides could continue along their current paths even without any arms control limits. Indeed, the Administration argues that the current rough balance of forces between the United States and the Soviet Union, coupled with weakness in the Soviet economy, would preclude any major expansion by the USSR.

On the other hand, the Soviet Union has already developed, or is deploying, numerous new strategic weapons systems. Both the Central Intelligence Agency (CIA) and the Department of Defense (DoD) have projected substantial potential for growth in Soviet nuclear weapons in the absence of arms control limits, while also noting that such an expansion would not necessarily be undertaken.

The CIA, for example, recently testified that--in the absence of arms control limits--the Soviet Union could have 21,000 nuclear warheads by the mid-1990s with a robust but not maximum expansion. This would provide it with about 6,800 to 7,400 more warheads than the United States would have without procurement of systems above and beyond current plans. If the United States were to match such an expansion, it would require a huge increase in U.S. forces: for example, adding about 867 more MX missiles in Minuteman silos or 36 more Trident submarines with Trident II missiles or 270 more bombers each carrying 28 weapons. The cost of such an expansion would vary widely but could add tens of billions of dollars to U.S. costs as well as greatly increasing Soviet expenditures.

A Soviet buildup could also threaten the ability of certain U.S. forces--particularly land-based forces--to survive a Soviet attack, a key element of the U.S. strategy for deterring nuclear war. For example, assuming the Administration deploys a baseline force of 500 small intercontinental ballistic missiles (SICBMs), the Congressional Budget Office (CBO) estimates that close to 50 percent of the SICBMs would survive the threat anticipated under SALT-type restraints. That percentage could fall to less than 15 percent by 1996, if the USSR were to enlarge its forces as described above. The survivability of SICBMs could, however, be preserved in several ways-most cheaply by expanding the area over which these mobile missiles are deployed. An expansion of Soviet forces could also have important effects on the ability of other nuclear forces to survive, such as the 50 additional MX missiles that the Administration is currently considering and the bomber force. Submarines at sea are the only systems whose survivability would not be affected by an expanded Soviet force.

This paper, which is a preliminary analysis, addresses these issues, beginning with a discussion of the balance of strategic forces between the United States and Soviet Union and likely trends assuming continuation of SALT-type restraints.² Next the paper turns to possible Soviet force expansion in the absence of arms control limits. Finally, the report discusses possible U.S. responses to any Soviet buildup, focusing on the effects on land-based forces, because they are today the most vulnerable leg of the U.S. triad and because solving their vulnerability has been the most complex and contentious issue of the U.S. strategic modernization effort.³

Nothing in these discussions should be taken as a CBO forecast of future U.S. or Soviet behavior; that cannot be known. This paper does, however, suggest a range of possible responses in the absence of arms limits.

This document is available in its entirety in PDF.

1. Note that the major constraints were placed on the number of launchers that could be maintained by each country, not the number of warheads. Numbers of warheads on existing types of missiles, however, were limited to the maximum number that had been tested.

2. These subjects will be covered in detail in a forthcoming Congressional Budget Office study.

3. The triad includes three segments of strategic nuclear weapons systems: land-based missiles, missiles launched from nuclear submarines, and missiles or bombs launched from strategic bombers.