You could argue that the 13-year-old West German coalition government--Helmut Schmidt's Social Democrats and the faithless Free Democrat minority--succumbed to overexposure, tired blood, the ague of internal chills and fevers. What with a stagnant economy, ragged Alliance relations, the dashing of d,etente's best hopes, you would thus expect the Germans to turn to something dynamically new.

You would expect, that is, a substantial transformation of the German political scene. Judging from the gleeful hand- rubbing in White House circles, you might also expect some significant improvement in German-American relations: on the Soviet gas pipeline, on defense issues, on a common approach to the Soviet Union, on economic policy. The new chancellor, Helmut Kohl, is some 20 years younger than his predecessor; he is a wily politician, avowedly "pro-American," a staunch Alliance man. He and his associates are not given to any of those socialist-neutralist hangups that made Schmidt such a trial for the Reagan true believers.

And yet, you would be hard put to find, in the unique process that brought Germany's change of government, what might be called a "mandate" for anything particularly dynamic or even strikingly new. The people did not speak.

The "constructive no-confidence" vote that turned out Schmidt, and brought in the Christian Democrats in coalition with the flip-flop Free Democrats, is entirely constitutional. It was designed for precisely the kind of political mess that West Germany had gotten itself into. But this hasn't stopped the storm of criticism that it was somehow "immoral" or "un-Christian" to deny the electorate their voice. That's one handicap Kohl starts out with.

He must count, moreover, on the support of a Free Democratic Party that itself has been sorely weakened, not only by the look of rank opportunism in its change of partners but also by its sorry showing in recent state voting. And just as Schmidt was in chronic conflict with his own party's left, Kohl does not have what you might call a cozy collaborator in the feisty, rightist leader of the Christian Democrats' Bavarian wing, Franz Josef Strauss.

And then there's the Green Party. This footloose, freewheeling amalgam of pacifist, neutralist, environmentalist, anti-establishment youth has no clearly defined ideological leaning, either left or right. But it does have a growing following and a real potential for replacing the Free Democrats as a coalition power broker if the Free Democrats cannot recover their strength.

All of this argues for the full use of Kohl's vaunted manipulative skills as a domestic politician. He needs to gather momentum -- quickly. He must be seen to be dealing with the formidable fiscal problems he confronts, with unemployment, and with a whole host of strong emotional, ideological and political undercurrents roiling the younger generation in Germany. For many reasons that may not be of his own making, this may prove impossible.

On the other hand, had Helmut Schmidt hung on beyond the eight years he had already served as chancellor, the prospect was almost certainly one of slow disintegration, a wider polarization between left and right, creeping government paralysis. There might also have been a worsening in relations with the United States. Where Schmidt often treated Ronald Reagan as a schoolmaster might treat a slow-witted student, Kohl will be far more compatible.

But most of the wiser heads here seriously doubt that this will bring anything more than marginal changes in substance: a little more enthusiasm for deployment of theater nuclear forces in Europe late next year, if no controls on these weapons have been negotiated with the Soviets by that time; perhaps a little more readiness to finesse the nasty transatlantic fight over the Soviet pipeline with an agreement among all Alliance members to take a tougher line in the future on trade with the East.

Had there been a quick election (the second alternative), the consequences could have been even more chaotic, with the FDP effectively wiped out as a national political force, and the essentially rudderless Greens a factor that would somehow have to be reckoned with.

The third alternative -- the one that was taken -- will give the new government time to consolidate its position before the new elections it has committed itself to, presumably early next year. It was the wisest, safest choice. But when you have said that, in full contemplation of the alternatives, you have not said much.