Washington — The report that Soviet agents have been using a chemical powder to track the movements of United States diplomats in Moscow is not, by itself, likely to sink the summit. But by announcing the Soviet action in such a dramatic and public way, the Reagan administration has reinforced the tough, confrontational approach it will take to Geneva for the November summit with Soviet leader Mikhail Gorbachev.
``It's part and parcel of a constant adversarial relationship,'' a State Department official says of Wednesday's announcement. ``You're dealing with rough people and a lot of them are not very scrupulous in the way they use power.''
``The incident shows an utter disregard for any diplomatic niceties,'' adds Soviet expert Mikhail Tsypkin of the Heritage Foundation. ``It's just one more demonstration of how basically far apart the two countries really are.''
US officials disclosed Wednesday that since the 1970s, Soviet agents have been using a chemical powder called NPPD to monitor movement of US Embassy officials and their contacts with Soviet citizens.
The Soviet news agency Tass said Thursday that the Soviet government categorically denied the US allegations, saying such claims were designed to ``poison the atmosphere of relations between our two countries and to fan hostility toward Soviet people.''
According to a State Department spokesman, the colorless, odorless powder is applied to everyday objects, like car steering wheels. When diplomats make clandestine calls -- on Soviet dissidents, for example -- they unwittingly leave behind chemical traces on a doorknob or piece of furniture. KGB agents later search the homes for these traces. Sometimes the Soviets place the ``spy dust'' where the diplomat steps on it, so that footprints are left behind.
Speaking from California, White House spokesman Larry Speakes said Wednesday the use of spy dust poses ``serious dangers'' to US-Soviet relations. The issue might be raised when President Reagan meets with Mr. Gorbachev in November, he added.
But administration officials say the announcement is not part of a presummit public-relations strategy. Instead, they say a sharp increase in the use of NPPD, combined with the chemical's known health dangers, left them no choice but to go public with the announcement now. According to laboratory tests, NPPD is capable of causing genetic mutations and possibly cancer.
The announcement points to an increasingly hard-line administration attitude toward the Soviets -- an approach experts say is designed to improve US bargaining leverage at the Geneva summit. In recent weeks, the administration rejected Soviet proposals to ban testing of nuclear weapons and to convene an international meeting on peaceful use of space.
In addition, national-security adviser Robert C. McFarlane delivered a sharp attack on the Soviets Monday, saying that ``even incremental improvements'' in superpower relations would be difficult without a major shift in Soviet arms policy and human rights practices, and an end to foreign military actions.
Wednesday's announcement may also be calculated to draw US public attention away from Monday's announcement that the US would soon resume testing antisatellite weapons, some experts say.
``Now that they've made their point to the Soviets, it's desirable, for domestic reasons, to shift the focus to Soviet misdeeds,'' says Raymond Garthoff of the Brookings Institution.
But many critics say the administration's aggressive public criticism has needlessly aggravated US-Soviet relations.
``There's nothing wrong with quietly communicating our displeasure with their action,'' says retired Rear Adm. Eugene J. Carroll of the Center for Defense Information. ``But they've turned the spy-dust incident into a media event. They've clearly intended to make this as confrontational as possible. I can't think of a worse approach to the summit.''