A secret report submitted to President Reagan by the National Security Council reveals that Soviet arms control cheating is more serious than the White House publicly admits, it was learned yesterday.
The administration listed nine cases of Soviet cheating in the latest unclassified arms violations report sent to Congress Dec. 23.
But the secret NSC report of the same date lists a 10th major violation, as well as greater detail than the White House disclosed on the extent of Soviet efforts to circumvent or exceed limits set by past treaties and agreements.
The report identifies the 10th violation as the "throw-weight of a certain SLBM." Throw-weight is a measure of a missile's nuclear warhead-carrying capacity.
Sources said the missile in question is the submarine-launched SS-X-23 missile. They said the missile's throw-weight violates limits on heavy missiles set by the 1979 SALT II arms control treaty, but the violation was not included in the public report to Congress because its detection involved sensitive equipment.
Details of the violation and evidence supporting it were not described even in the secret report to Mr. Reagan, other than a notation that "the issue is addressed separately."
The report, prepared by analysts from the Arms Control and Disarmament Agency and the Central Intelligence Agency, also contains details on Soviet deployment of new anti-ballistic missile system components, and on deployment and concealment of mobile intercontinental ballistic missiles.
The SALT II treaty was signed in 1979 but never ratified by the Senate. Since 1982, the United States and the Soviet Union have agreed to follow a "no undercut" policy, under which they observe the treaty as a political commitment, rather than a legal obligation.
The secret report contains details of U.S.-Soviet diplomatic exchanges that indicate the Soviets consistently dismissed American charges of Soviet cheating, even when the evidence offered by U.S. officials was overwhelming.
The amount of attention given Soviet violations of the 1972 SALT I Anti-Ballistic Missile Treaty in the secret report seems to indicate the administration is most concerned about those violations.
The report indicates the Soviets are continuing work on a giant radar at Krasnoyarsk in Siberia, that the United States has previously charged is a serious violation of the ABM Treaty.
The Soviets claim the radar is being used to track satellites, but the secret report states: "Continuing construction and the absence of credible alternative explanations have reinforced our assessment of its purpose."
"Despite U.S. request, no corrective action has been taken," it says.
The secret report also provides more detail about potential Soviet violations of the ABM treaty's ban against nationwide and mobile ABM systems. The treaty allows each nation to have one ABM system at one fixed and designated site. The Soviet system is located around Moscow. There is currently no U.S. system.
The report concludes that the evidence of a Soviet violation of the ban on mobile systems is "ambiguous" but their activities "suggest" the Soviets are developing mobile components that could be quickly deployed to create a nationwide system.
It also contains a charge, omitted from the public report, that the Soviets can reload ABM launchers in a little more than two hours, possibly faster. Such a rapid reload capability would be crucial to an effective ABM defense, which would face waves of incoming warheads.
The report also reveals more information about the Soviet SA-X-12 surface-to-air [SAM] missile's ABM capability. The SA-X-12 is nominally an air defense missile for use against aircraft, but the Pentagon and other analysts have suggested that the missile also has capability against some ballistic missiles.
The report says the missile has been tested "at least once against at least one type" of short-range ballistic missile. Capability against such missiles, the report notes, would also give the SAM the ability to "intercept at least some types" of ICBM warheads.
The report indicates that U.S. intelligence also has detected three types of potential violations of treaty rules banning joint testing of tactical and ballistic missile defense systems: the firing of SAMs at test warheads, ABM radars operating and SAM radar operations during tests.
"There have been numerous events during 1985 which include one or more occurrences of each of the three general classes of activities cited above," the report states.
The report cites the Soviet SS-25 mobile ICBM as the basis for several violations of the SALT II treaty.
The treaty allows each side to "flight test and deploy" only one new type of ICBM. The Soviets announced in 1984 that the SS-X-24 rail-mobile ICBM - now being deployed - is their permitted new missile.
They claim the SS-25, also being deployed, is a permitted modernization of older-generation SS-13 missiles. But the report further documents U.S. charges that U.S. intelligence has determined that since the SS-25 was first tested in early 1983, more than 20 flight tests have shown that the SS-25 is "a completely different missile [from the SS-13]."
Also, under SALT II rules governing modernization of missiles, the Soviets must limit growth in warhead throw-weight to no more than 5 percent of the older missile's capacity. The SS-25 carries 50 percent more warhead weight than the SS-13, the report states.
Notification by Soviet officials last October that the SS-25 had been deployed also led to a new U.S. charge of exceeding SALT II limits on ICBM warheads.
The report shows that the Soviets had deployed between 2,522 and 2,544 warheads by deploying the SS-25 and dismantling some SS-11 launchers. SALT II limited the Soviets to no more than 2,504 warheads.
According to the report, a letter to U.S. officials from a Soviet arms negotiator last August stated that the Soviet warhead level had "not at any period of time exceeded the specified level [2,504]."
The Soviets also pledged under SALT II not to produce or deploy any SS-16 missiles.
But the report discloses that since last year the United States has "noted activities that indicate the Soviets probably are removing SS-16 missiles and equipment from Plesetsk." That amounts to deployment, the report says.
Two other charges related to the SS-25 concern the Soviet concealment of two missile test silos and a single-bay garage launcher at Plesetsk which impedes verification provisions of SALT II - and the coding of missile test data relayed to ground stations during test firings, known as "telemetry."
Soviet officials told U.S. arms negotiators in 1984 that Soviet forces were under strict orders not to camouflage or conceal missiles and launchers, the report states.
"While we have routinely observed what is apparently the SS-25 launcher under camouflage or concealment near the SS-25 garage, we have never observed an uncovered missile canister and its associated launcher at the test site," the report states.
Further Soviet denials of concealing missiles and launchers made during diplomatic exchanges last spring were countered by U.S. officials' charges that "numerous instances" of concealment appear to be "standard practice in that test program," the report concludes.