Soviet Fears Imperil Conventional Forces Pact : Arms control: Moscow is worried about changes in Eastern Europe and the huge U.S. military buildup in the Persian Gulf.

The U.S.-Soviet plan to complete the treaty slashing the superpowers’ conventional forces in Europe by the end of the year is being jeopardized almost at the last minute by concerns in Moscow over the rapid changes in Eastern Europe and the massive American military buildup in the Persian Gulf.

Along with the Gulf crisis and new problems that have developed in the Strategic Arms Reduction Talks, the treaty on conventional forces will be on the agenda when President Bush and Soviet President Mikhail S. Gorbachev meet Sunday in Helsinki.

The Kremlin, responding to the changes in Eastern Europe, wants to reopen negotiations over how many U.S. and Soviet troops could remain in Europe, Administration officials say--a move that may derail the whole treaty on conventional forces in Europe unless Bush and Gorbachev resolve the problem at the summit meeting.

Final agreement on the treaty is further complicated by concern among Soviet military leaders that CFE, as the agreement on conventional forces in Europe is known, could prevent them from concentrating troops in southern Russia to balance the U.S. buildup in the gulf, only about 700 miles from the Soviet frontier.

Bush and Gorbachev have publicly pledged to complete the treaty by the end of this year. And the crucial question of how many troops each superpower would be entitled to deploy in Europe was supposedly settled last February.

But now, with Moscow’s newly independent satellite nations demanding speedy withdrawal of Soviet troops from their territory, Kremlin leaders realize that they will soon be unable to deploy even the scaled-down forces permitted under the CFE agreement. As a result, they want to negotiate still lower limits on both sides.

Moreover, Gen. Vladimir N. Lobov, commander of Warsaw Pact forces, recently issued a public warning that the U.S. military buildup in the Mideast could jeopardize the CFE talks. Soviet Foreign Ministry spokesman Gennady I. Gerasimov quickly denied that the Kremlin shares Lobov’s fears about the buildup. There was “no direct link” between the arms talks and the Persian Gulf crisis, Gerasimov said. But Lobov’s comments indicate a split within the Soviet government on the issue that could impede progress toward completing the deal.

The U.S. Defense Department is also interested in re-examining the question of exactly how many troops each side could keep in Europe. Some Pentagon officials see such renewed negotiations as an opportunity to get higher ceilings for U.S. forces on the periphery of Europe, where they could be more useful in Mideast and other Third World crises.

But sources said these Pentagon officials are out of step with other U.S. agencies and will not prevail over State Department and White House officials, who believe that reopening the complex issue of troop ceilings would hopelessly delay CFE.

Already, some arms control experts fear that the gulf crisis is distracting the White House from arms control issues just as the intense “end games” of both negotiations demand close attention.

Spurgeon M. Keeny Jr., director of the private Arms Control Assn., complained that the crisis “could easily result in extended delay” of both arms negotiations, which have seen little progress since the last U.S.-Soviet summit meeting in June.

Last February, Moscow agreed to a ceiling of 195,000 men each for the U.S. and Soviet forces in Central Europe, plus another 30,000 men for the United States on the Continent’s periphery.

But Moscow now recognizes that it will be unable to keep 195,000 men in Eastern Europe. Its 400,000-man force now in East Germany will be removed in less than four years, and its troops in the other former satellites will be gone by mid-1991. As a result, it wants to impose greater limits on U.S. forces in Central Europe.

An excuse to reopen the manpower question was found in the Soviet-West German agreement in July to limit a unified German army to 370,000 men. With that ceiling, Soviet Foreign Minister Eduard A. Shevardnadze told Secretary of State James A. Baker III in Irkutsk, Siberia, last month, fewer U.S. and Soviet forces would be justified in Central Europe.

The Pentagon, for its part, wants to increase the 30,000-troop ceiling on U.S. forces on the European periphery--in Britain and in NATO nations along the Mediterranean--to about 50,000, sources said. If it cannot win such an increase, the Pentagon would settle for a joint ceiling for all of Europe, in which it would have greater flexibility to move forces around the Continent as needed.

The other major outstanding issue in CFE, officials said, is limits on numbers and kinds of aircraft. The Soviets have recently moved closer to the North Atlantic Treaty Organization position on limits but major differences remain. Similarly, the United States wants to constrain land-based Soviet aircraft that are capable of attacking U.S. warships, whereas the Soviets want to constrain U.S. carrier-based aircraft.

The disagreement may be dealt with by putting aside the aircraft issue until follow-up negotiations.

So far as efforts to complete the Strategic Arms Reduction Treaty are concerned, the major political issue--a “treaty buster,” in arms control jargon--that could require resolution at the Bush-Gorbachev summit meeting is a Soviet effort to halt U.S. cooperation with Britain’s nuclear weapons programs.

U.S. officials maintain that Bush would rather forgo a START treaty than end the Anglo-American partnership on nuclear weapons. Officials hope Bush will tell Gorbachev to give up that effort.

Somewhat lesser difficulties involve flight-testing of the massive Soviet SS-18 missiles and continuous on-site monitoring posts at missile production facilities.

At first, the Soviets seemed ready to accept any kind of inspection regime, but now they prefer that no new posts be created beyond the one set up by each side under the existing intermediate-range missile treaty to keep tabs on production of those weapons.