WASHINGTON — The treaty banning ground-launched medium-range missiles that President Reagan and Soviet leader Mikhail S. Gorbachev will sign today provides for elaborate and intrusive measures to ensure compliance, but it still cannot guarantee that there will be no cheating.
Conservatives are already calling this sufficient reason for the Senate to refuse to ratify the historic treaty. But treaty proponents insist that the Soviets are unlikely to cheat, even though they might get away with it, because the advantages they might gain from cheating pale beside the international condemnation they would receive if they were caught.
"The Soviets can legally deploy longer-range missiles to aim at European targets now covered by their medium-range missiles," explained Kenneth L. Adelman, outgoing director of U.S. Arms Control and Disarmament Agency. "Why cheat by keeping the illegal missiles and risk getting caught?"
During the first several years of the treaty, the probability of catching any cheating will be less than 50%, according to many experts, because of initial uncertainty about whether each side has told the other about all the missiles that it has squirreled away.
The odds will increase, perhaps to as much as 90%, during the 13-year life of the treaty--thanks largely to the fact that whichever side decided to cheat would have to test its missiles to ensure that they still worked, and tests are relatively easy for the other side to detect.
When tested, every type of missile has a distinctive "signature"--the heat from its rocket, for example, or radio signals from its various internal mechanisms--that can be recognized by the other side.
"The Soviet Union has 7 million square miles of area, and our inspectors can't visit 6.99 million miles of them," said a U.S. official who asked not to be identified. "But they can't hide a missile flight test."
In all the history of nuclear arms control, this is the first treaty that has called on the superpowers not just to limit the future deployment of missiles but to dismantle weapons they already have. The treaty provides that each side will eliminate its nuclear missiles that have a range of 300 to 3,000 miles, along with associated equipment such as launchers. No additional missiles can be produced, stored or deployed.
At the insistence of the United States, the bulk of the treaty's 200 pages deal with verifying compliance with the treaty. The verification system that has been established is the most elaborate and intrusive the superpowers have ever agreed to in an arms accord.
Each side will have inspectors on hand as the other destroys its weapons. They will be able to watch as nuclear warheads are removed, to be later recycled in other weapons. They will see nose cones and missile frames crushed or otherwise destroyed, rocket motors burned and the axles of mobile launching vehicles cut in half. For the first six months, each side can destroy up to 100 missiles by launching them harmlessly into a test range in the ocean or the Central Asian desert, according to U.S. officials.
In an effort to ensure that neither side simply replaces old weapons with new ones, each will continue to be able to keep a close eye on the other. Soviet inspectors will establish a permanent presence just outside the gates of a missile plant in Magna, Utah, 16 miles from Salt Lake City; U.S. inspectors will do likewise at a missile plant in the Ural Mountains.
More than that, each side, with only nine hours' warning, will be able to make a fixed number of visits each year to the declared missile facilities of the other to make sure that nothing is going on that the treaty prohibits.
Each nation's missile sites--production, maintenance and storage facilities and bases where the missiles are deployed--are identified in an annex to the treaty by longitude and latitude, although compiling all the data proved difficult.
The Soviets were late in providing the information the United States needed, and the U.S. side erred in giving one set of coordinates; the site turned out to be a lake. After the Soviets protested, the coordinates were corrected, according to a senior U.S. official.
All the declared sites will be inspected by the other side. But each side might also have hundreds of additional missiles--estimates range up to 300, plus as many launchers--hidden in distant warehouses. Inspectors cannot visit those sites.
The reason "we can't go anywhere, anytime, anyplace in the Soviet Union," said a senior Administration official, "is because we don't want the Soviets to go anytime, anywhere, anyplace in the United States."
"There will clearly be opportunities to cheat, lots of them," said Michael Krepon, verification specialist for the Carnegie Endowment for International Peace.
'Will Never Be High'