W. German scale-tipping 'third party' teeters on edge

Can the tiny but scale-tipping Liberal Party survive? Can conservative Chancellor Helmut Kohl survive? And for that matter, can West Germany's stable politics of the center survive?

These are the melodramatic questions being asked in the wake of the long-awaited resignation of veteran Economics Minister Otto G. Lambsdorff at midnight June 27.

The most serious threat of extinction faces the Free Democratic Party (FDP). For almost a quarter of a century this classical liberal party, with its right wing's emphasis on a free market and its left wing's emphasis on civil rights, has decided whether right or left would rule West Germany.

And once it has made this coalition decision, it has braked its senior partner's right or left tendencies and pulled the government toward the center.

This is a role that has kept enough middle-of-the-road burghers voting for it in every general election to clear the 5 percent minimum for seats in the Bundestag. But it is also a role that has repeatedly brought charges of betrayal from an angry right wing (the Bavarian Christian Social Union, the present coalition) or left wing (the more ideological Social Democrats in Chancellor Helmut Schmidt's coalition from 1974 to 1982).

Count Lambsdorff, a free-market champion of the first order, precipitated the Liberal Party's shift to the present center-right coalition back in 1982. That made him the special target - along with party chairman and Foreign Minister Hans-Dietrich Genscher - of the left wing. What forced Lambsdorff's resignation now was his indictment on charges of bribery in connection with the scandal over party contributions from the Flick industrial conglomerate.

Lambsdorff continues to protest his innocence, but he says he cannot prepare a trial defense and conduct Economics Ministry affairs at the same time. His resignation deprives the FDP - and the government - of one of its most capable ministers - at a time when the party is already reeling from other blows.

The FDP failed to clear 5 percent in this month's Europarliament elections - after failing similarly in six out of West Germany's 11 states in recent years. Mr. Genscher is no longer popular, even in his own party, and he has now promised to resign from the FDP chairmanship next year (or possibly even this year) to make way for younger leaders. Yet the younger leaders are slow in appearing, and Lambsdorff's successor and possibly also Genscher's future successor as party chairman is Martin Bangemann, the leading Liberal candidate (and noneconomist) who didn't make it into the European Parliament.

The question of survival is less acute for Christian Democratic Chancellor Helmut Kohl. In the short run he has managed to keep the Economics Ministry in the hands of the Free Democrats and out of the hands of his arch rival, Christian Social Union chairman and Bavarian Premier Franz Josef Strauss. But in the longer run his neutralization of the right-wing Bavarians within his coalition by the center Liberals is being jeopardized.

Nor does Mr. Kohl have much personal political capital to throw into his suppressed feud with Strauss. He won the March 1983 election with a resounding majority, but his standing in opinion polls has dropped steadily ever since, and he is the brunt of numerous cruel jokes impugning his intelligence.

At the moment Kohl has two successes to bolster him: the resolution this week of the five-year-old European Community financing battle and the pending resolution of the West German metalworkers' strike (through the arbitration of a Social Democrat). But it is not yet clear how much their momentum will help Kohl.

Strauss' reading of the FDP's troubles at this point could be summarized in the phrase ''good riddance.'' He argues that the Conservative Union parties could win a majority of their own, given the conservative German voters' fear of radicalism from the new environmentalist-pacifist Greens party on the left.

Hardly anyone in Kohl's Christian Democratic Union shares Strauss's conviction, however. The CDU fears that a collapse of the Liberals would have just the opposite effect. Instead of giving the conservatives a majority it might well leave the conservatives and Social Democrats in deadlock short of 50 percent - and leave the unpredictable Greens as the new scale-tipping ''third party'' in West Germany. The Greens have already surpassed the Liberals in the European elections.

That in turn raises the specter for some of a future Social Democratic-Green coalition on the federal level - a pattern that is being experimented with in the state of Hesse. Such a federal coalition would strengthen the Social Democratic left wing and eliminate the Liberals' constant pull to the center of the last 25 years.