The United States is expelling 25 diplomats from the Soviet mission to the United Nations. Although State Department spokesman Bernard Kalb stressed that the move was not directly related to the case of an American journalist, Nicholas Daniloff, who is being held in Moscow, it will undoubtedly further complicate already strained US-Soviet relations.
The move comes just two days before US Secretary of State George P. Shultz is due to meet Soviet Foreign Minister Eduard A. Shevardnadze to finalize plans for a summit later this year between President Reagan and Soviet leader Mikhail Gorbachev.
Mr. Shultz has already indicated that the Daniloff case will become the central focus of the meeting if the American correspondent is still being held in Moscow, and he has also warned of eventual American retaliation.
The Reagan administration is coming under increasing pressure for its handling of the Daniloff affair, which has overshadowed many other aspects of superpower relations. But it's also trying to keep negotiations on other issues -- such as nuclear arms control and the summit -- on track. There are mixed signs on the success of this effort so far.
In Geneva, US arms control negotiators pointedly brought up the Daniloff affair at the start of a new round of talks. Chief US negotiator Max Kampelman blamed ``increased tension in all of our relations'' on Soviet treatment of Mr. Daniloff.
Still, Mr. Kampelman and other members of his negotiating team are said to have been given new instructions allowing them greater flexibility. Reportedly, the negotiators will be seeking reductions of 30 percent -- rather than 50 percent -- on US and Soviet long-range nuclear missiles and heavy bombers.
While that might increase the prospects for agreement, it would also mean a smaller reduction in the two sides' nuclear arsenals than originally envisaged under ``deep cuts'' proposals put forward by both sides.
Meanwhile, US negotiators in Stockholm, at a 35-nation conference on ``confidence-building measures'' aimed at preventing the accidental outbreak of war in Europe, are also studying a new Soviet proposal involving verification of troop movements.
The proposal would allow Western military observers to make aerial checks on Soviet troop movements -- but only if they are ferried overhead in Soviet planes. The US and some other Western nations had favored the use of planes provided by neutral nations. Still at issue: the kinds of cameras and surveillance equipment that observers would be allowed to use.
Both moves -- the new instructions for Geneva negotiators and a decision to explore the Soviet proposal at Geneva -- are being interpreted as rebuffs to so-called ``hard-liners'' in the administration, who question the value of arms control agreements with the Soviets.
Some of these hard-liners are seizing upon the Daniloff case as an example of Soviet bad faith. And, ironically, the Soviets -- by not letting Daniloff leave -- seem to be buttressing their arguments.
White House spokesman Larry Speakes says negotiations to secure Daniloff's exit from the Soviet Union are continuing. Meanwhile, the correspondent for U.S. News & World Report and his wife, Ruth, are living at the American Embassy in Moscow.
Daniloff was arrested by the Soviet secret police after a Soviet diplomat at the United Nations was picked up by the Federal Bureau of Investigation and charged with espionage. According to the US, the Soviet diplomat, Gennady Zakharov, was only one of a ``nest of spies'' operating from the UN.
The United States maintains that the Soviet, Byelorussian, and Ukrainian missions to the UN are far in excess of the size needed to conduct diplomatic business, and it charges that many of the diplomats are spies. The Soviets have denied the charges, and have, according to the State Department, made no effort to comply with an Oct. 1 deadline to reduce the mission's size. The Soviets argue that the Reagan administration's order to reduce the mission is a violation of the UN Charter.
Because the Soviets have failed to act, Mr. Kalb said Wednesday, the United States handed over a list of 25 Soviet diplomats who must leave the country by Oct. 1. Under the US order, 80 more Soviet diplomats must leave over the next 18 months, to reduce the total size of the missions from 275 to 170. ``It is not related to any other issue or case,'' said Kalb, who conceded nonetheless that some might draw a contrary conclusion.