W. Germany is key to whether Europe joins US `star wars' effort. United States hopes Bonn will support the research program and lead the way for the rest of Europe

As West Germany goes, so goes Europe. Hence the intense campaign to enlist Bonn for or against the American research program into space-based defense -- the Strategic Defense Initiative (or ``star wars''). Hence the distress of both promoters and critics of SDI over the Bonn government's ambivalence, pending a decision in September on whether and how Germany should participate in the project.

The principal motivations appealed to in this contest are technological rivalry, loyalty to the United States, and strategic worries.

The principal players in the contest are: Chancellor Helmut Kohl, his split Conservative party, the Pentagon and its close German friends, Foreign Minister Hans-Dietrich Genscher, and industrialists in the armaments field. (The West German Defense Ministry is surprisingly quiet.)

So far this mixture has produced a government in Bonn that expresses generalized enthusiasm about SDI but shies away from making any practical commitment to German participation in it.

The present mood can be explained only by looking at the history of the past year and a half. But first, a bit of background to explain the present ambiguity.

Curiously -- given the Bonn Defense Ministry's reticence -- the strongest European misgivings about SDI were first uttered by West German Defense Minister Manfred W"orner in April 1984, largely on the basis of SDI's potentially negative impact on European defense. Dr. W"orner's comments reflected concerns on the part of his ministry's professional staff and top generals that superpower strategic defense might eventually neutralize nuclear weapons and leave West Germany at the mercy of the superior Soviet-bloc conventional forces -- and that the project would certainly drain money away from that crucial conventional defense.

W"orner was quickly reined in by Foreign Minister Genscher and especially by Chancellor Kohl -- who is good friends with President Reagan -- on grounds of loyalty to the US in general and to a pet project of President Reagan in particular.

The Foreign Ministry, although it was wary of SDI's possible impact on international stability and arms control, was even more leery about the prospects of going through another bruising US-European controversy like the 1980-83 debate in Europe over whether to deploy NATO medium-range nuclear missiles.

The chancellery took a basically agnostic approach to SDI but thought that if Bonn wished to have any say in later SDI decisions, it was prudent to go along with a project that Reagan was so clearly going to pursue, whatever the Europeans might think about it. Besides, both thought, the strategic assessment of SDI could be put on hold, since deployment decisions would not be made until someone new was in the White House.

Kohl took to praising SDI but noting that its development must of course not ``decouple'' American and European defense -- or undermine NATO's ``flexible response'' (the option of either conventional or nuclear defense) without replacing it with some demonstrably better form of defense.

This stance was in fact not unwelcome to the West German Defense Ministry. Some of the older generals shared the zeal of American SDI enthusiasts and hoped that SDI might once again give the US a military lead over the Soviet Union. Some of W"orner's aides were strongly imbued with loyalty to Reagan's America as an overriding principle.

And both uniformed and civilian professionals in the ministry had for a long time been worried about the growing threat of Soviet shorter-range missiles to fixed targets in West Germany. They hoped SDI research might yield technologies that -- whatever their eventual use or nonuse in strategic defense -- could help stave off this shorter-range threat.

Still, these military issues were a question for the 1990s or the 21st century. Soon a much more urgent consideration began to preoccupy West Germans -- the yearning not to be left behind the US (and Japan) in the technological surge promised by the dollars pouring into SDI. This concern became especially acute this year as the US invited its allies to join in SDI research, and attitudes to SDI became an immediate policy issue.

Baden-W"urttemberg Premier Lothar Sp"ath and Bavarian Premier Franz Josef Strauss of southern Germany's ``Silicon Valley'' became the champions of Germany's technological future. They chastised Chancellor Kohl for being lukewarm in his support of SDI.

They, and various industrialists who hoped to get lucrative contracts out of SDI, lobbied hard for the government to promote West German participation in SDI research. They figured that initial involvement would develop a momentum and constituency of its own that would assure continued involvement in the future.

The right wing of the Christian Democratic Union and its spokesman, Bundes-tag majority leader Alfred Dregger, also took up the cause. Their assessment was that if both Moscow and the West German Social Democrats were adamant opponents of SDI, it must be a good project and one on which the party should take a clear pro-American line.

The center wing of the CDU was more dubious. Dr. Dregger's parliamentary deputy, Volker R"uhe, noted that West Germany should not have unrealistically high expectations about US largesse in sharing high-tech with allies. Finance Minister Gerhard Stoltenberg acted as the usual jealous guardian of the purse strings.

And Research Minister Heinz Riesenhuber, who thinks privately-funded research is far more productive than government-subsidized know-how, stood by the old conservative precept of the least possible government meddling in the free economy.

Then in May at the economic summit in Bonn -- although Kohl still mentioned his usual provisos -- the chancellor endorsed SDI especially warmly for his American guest, Ronald Reagan -- at the same time that Kohl's closest European ally, French President Franois Mitterrand, was rejecting SDI especially vehemently.

The fact that just what Mitterrand was rejecting was as vague as what Kohl was approving somehow got lost in the drama of the French-German rift. That rift along with a growing realization that there could be major problems of technology transfer in any cooperation with the US gave West German SDI sceptics a chance to tilt the scales back a bit.

Prominent among them this time around was Foreign Minister Genscher of Kohl's junior coalition party, the Liberals. He at first expressed his anxieties about SDI more cautiously than did his British colleague, Sir Geoffrey Howe, primarily because Genscher didn't want to encourage Moscow in any wedge-driving between the US and Europe.

But he thought that SDI posed some real strategic conundrums, that Germans should not be stampeded into supporting it -- and that any German participation in developing shorter-range antimissile weapons (ATBMs) would have to be approached very carefully lest it revive the antinuclear protest and charges that Bonn was helping Washington evade restrictions in the superpower antiballistic missile (ABM) Treaty of 1972. He also thought the chancellery should not be taking so much foreign-policy initiative away from the Foreign Ministry on this and other issues. Tactically, Genscher lamented the German-French rift and urged its repair by giving more sympathy to France's out-of-the-blue proposal of last spring for a rival pooling of Europe's own (SDI-related) research in a project called Eureka.

There matters stood when Horst Teltschik, Kohl's foreign-policy adviser, visited Washington early this summer to get a more concrete idea of the US concept of European participation in SDI -- and especially to ask what assurance there would be that the US wouldn't just skim off top European researchers and technology, then bar European commercial application of the technology on grounds of security.

The mixed signals the team received did not go far toward resolving the Bonn government's dilemma. Washington said it would sign the memorandum of understanding Bonn wants to guarantee a certain degree of commercial access by German firms to technologies they help develop. But US practice leaves many West Germans unconvinced of the value of any agreement. Last weekend the European Community opted for Eureka.

The latest arguments in West Germany rage over whether development of an ATBM should be primarily a pan-European or a joint European-American task.