Washington — If the Soviet Union embarks on a strategic buildup to challenge the MX missile system, it would cost the United States tens of billions of additional dollars to ensure the system survives.
When compounded by the protests of environmentalists, who object to the proposed basing of the missile system in the Great Basin region of Nevada and Utah, a price tag of this magnitude could effectively force an abandonment of the current MX basing plan.
These assertions are made in a report on US defense options, and resources to fund them, for fiscal years 1982-86, recently released by the Congressional Budget Office (CBO). The study declares that the cost of an MX system could climb to as much as $106 billion.
By contrast with the Air Force's MX plan, which would deploy 200 MX missiles among 4,600 horizontal shelters at an estimated cost of $33 billion, the CBO assumes that the US needs 275 missiles and 5,828 shelters if it is to ensure that 1,000 warheads survive a Soviet first strike.
In making this calculation, it presumes that Moscow would adhere to the SALT II limit of 820 multiple-warhead intercontinental ballistic missiles (ICBM) and would not increase the number of warheads on each one.
The CBO claims that its envisaged missile deployment would cost $47 billion and an additional $8 billion in operating and support costs through fiscal year 1999.
If the Soviet Union decides to increase its strategic missile punch to respond to MX deployment, particularly in the absence of strategic arms limitations, it could place ICBMs with multiple warheads (called multiple independently targetable reentry vehicles, or mirvs) in its approximately 1,400 silos by 1987, according to the CBO.
Pointing out that the MX system is not expected to be finished until 1989, the CBO claims that Moscow could deploy such a force simply by maintaining its production rate of 125 missiles annually. "Adding these extra MIRVed ICBMS, even without increasing the number of warheads per missile above current levels, would give the Soviet 9,100 warheads on their MIRVed ICBMS," the report states.
To meet this threat, the CBO maintains that the US would require 350 MX missiles distributed among 9,159 shelters if it were to preserve 1,000 warheads, or some 100 missiles. The cost: $60 billion.
If the Soviet Union were to place a larger number of smaller warheads on the 820 MIRVed ICBMS permitted under SALT II (a practice known as "fractionating"), it could deploy 15,000 warheads, according to the CBO. A threat of this order would require 400 MX missiles and 15,120 shelters and cost $78 billion, it states.
"Finally, the Soviets could both increase the number of MIRVed ICBMS and fractionate their payloads, resulting in a total threat of 23,000 warheads," declares the report. "The cost of an MX system that ensured 1,000 surviving warheads after a Soviet first strike would then increase to $106 billion." This sum would be spent on 450 MX missiles and 23,485 shelters.
The CBO concedes that such improvements to missile systems would be expensive both for the United States and the Soviet Union.
It adds that it might be possible to limit the Soviet threat through future arms-control agreements and to reduce additional US costs by deploying an antiballistic missile (ABM) system rather than building more MX missiles and shelters. But it cautions that the deployment of any viable ABM system would "almost certainly" involve scrapping the SALT I ABM treaty banning such a system. "While the treaty is subject to review in 1982," it notes, "abrogation might be viewed as a setback for the arms-limitation process."
In the CBO's view "the combintion of possible cost increases and environmental concerns could compel changes in the MX system," particularly in its basing mode. Both factors are known to wrry Secretary of Defense Caspar Weinberger. He has said that he will examine the possibility of basing the MX at sea.
Noting that Congress has initially funded a number of strategic force improvements, the CBO claims that most of them would not enhance US strategic posture "until the late 1980s or beyond." It contends that the quickest way to enhance the nation's strategic posture would be to increase the number of strategic bombers on day-to-day alert. "Raising the alert rate from 30 to 40 percent, for example, would permit as many as 480 more nuclear weapons to be added to day-to-day alert status," it asserts.