Is the bargaining chip that many believe revived the arms control talks becoming a stumbling block? More and more America's futuristic plans for a missile defense in space are being seen in Europe as the issue on which the renewed United States-Soviet dialogue could collapse.
Concern is surfacing that the topic could hand the Soviet Union and Western antinu-clear protesters a powerful propaganda weapon that might rekindle the massive antimissile protests of recent years. They had cooled following the start of US missile deployments in Europe and the subsequent Soviet walkout from arms control talks.
This concern has been added to the long-held European reservations over the impact of the Reagan administration's Stategic Defense Initiative (SDI or ``star wars'') on European defense and strategy. For weeks, leaders such as British Prime Minister Margaret Thatcher, West German Chancellor Helmut Kohl, and French President Franois Mitterrand have barely hidden their discomfort at the US plans.
Just as in the US, there have been many skeptics who felt the project was not technically feasible or who believed it would initiate a new phase of the superpower armaments competition.
The original European fear was based on two main concerns: The first, which American officials have repeatedly sought to overcome, was the early belief in Europe that SDI, if it worked at all, would protect only the United States, leaving Western Europe vulnerable to nuclear missile attacks.
If US backers of the plan dispelled this initial suspicion, they did not completely remove the belief that this emphasis on defense, if shared by the Soviet Union as some Americans hope, would further erode the Western alliance's nuclear deterrent and make the British and French nuclear forces virtually useless.
These, according to officials here, were at the root of the anxieties expressed by European leaders since President Reagan first addressed himself to the topic. It was also this Western European concern which Mikhail Gorbachev, the Soviet No. 2, deftly tried to exploit during a December visit to Britain.
The French government in June, for instance, had proposed a five-year moratorium on work on antisatellite weapons, missile defenses, and the use of space for military activities. President Mitterrand referred to the project as ``overarmament.''
Even following Mrs. Thatcher's December discussion with President Reagan, British officials have been reported to be worried that the US would be unwilling or unable to limit the space defense project to the research phase. Mrs. Thatcher had publicly worried about the possible escalation by both superpowers into a new phase of the arms race.
She said if the United States proceeds beyond research, ``The other side will surely follow, and within but a short time we shall have the same military balance but at a higher level and at a higher cost.''
But more recently, Europeans have become apprehensive about the possibility that the apparent US reluctance to negotiate about the space research program at the newly resumed arms talks with the Soviet Union could be a costly miscalculation.
Reports have indicated that West Germany is especially concerned about a resurgence of antinuclear sentiment and demonstrations. German sources have been quoted as saying this unrest was quelled because it was the Soviet Union which broke off arms control talks with the US a year ago. But public opinion may turn against the United States again if the new talks break down because of a continued US refusal to bargain on the space program.
Many officials and other observers have signaled recently that the handling of this issue could lead to a repetition of the agonizing friction within the alliance in the early stages of the Euromissile deployment controversy.