European support for Washington in putting pressure on Iran and boycotting the Moscow Olympics is at once a foregone conclusion and a pipsqueak affair. So why all the fuss about the details?

The answer is that there is now taking place a kind of rehearsal of serious business -- a proto-crisis for the Atlantic Alliance. The central facts are that Russia is on the march, that Washington has no general strategy for checking Moscow and that, accordingly, the Europeans are looking for ways to get out from in between.

The Russians have brought their strategic power into parity with the American deterrent, beefed up their conventional forces and developed a capacity for intervention around the world. Their new power has already fueled wars in Southeast Asia, the Indian subcontinent, the Middle East and Africa. The invasion of Afghanistan was only the latest in a series of assertive moves.

The American response has long been characterized by weakness and indecision. Arms control was the main answer to the military buildup. Opportunities to confront Russia in the Caribbean, Africa, Southeast Asia and the Middle East were systematcally ducked.

The only reason Jimmy Carter reacted vigorously to the invasion of Afghanistan is that the seizure of the hostages in Iran had exposed the weakness of his foreign policy at the height of the primary season. In the circumstances, it is hardly surprising that, far from framing a general strategy, his calls for allied help on Iran and Afghanistan have been both unsteady in substance and erratic in tone. Even so, the European allies could have responded with grace and force.

Chancellor Helmut Schmidt depends heavily on U.S. support both for West German security and for his prospects in the elections this fall. He knew from the beginning that he would go along with Washington in putting pressure on Tehran and boycotting the Olympics.

But for economics, human and domestic political reasons, he also sets high store on the so-called Ostpolitik -- his policy of maintaining ties with Russia and the Soviet bloc, including East Germany. In the absence of any basic U.S. strategy for dealing with Russia, he came to fear the worst for his Ostpolitik. So he has been talking up the dangers of U.S. policy, invoking memories of the way Europe stumbled into World War I and even getting ready with the Russians on a visit to Moscow this summer. i

President Valery Giscard d'Estaing of France could have acceded even more gracefully to Jimmy Carter's call for help. France on its own bat condemned the affair of the hostages and the Soviet invasion of Afghanistan in the strongest terms.

But the Gaullist legacy stresses French independence from the United States, and the large block of communist voters in France makes that emphasis doubly advantageous. With no framework of American policy in place, the French president found it useful to go along with the United States for reasons of solidarity. To drive home his stance, France too is bargaining with the Russians -- even to the point where Giscard, who did not receive Secretary of State Vance on his last visit to Paris, has decided to receive Soviet Foreign Minister Andrei Gromyko.

Prime Minister Margaret Thatcher of Britain is positively gung ho on the American connection. Politically, nothing serves her interests better than to profile against the Labor Party's doubts her own government's show of support for Washington in Iran and Afghanistan.

But the British also want to get on with the French and Germans in Europe and with their various former colonies in Africa and Asia. Unconstrained by any grand American strategy, London has accentuated the North-South, as distinct from the East-West, nature of the present crisis. Lord Carrington, the foreign minister, has come up with an idea for a "neutral" Afghanistan. That not only sounds good to Indians, Pakistanis and other Third Worlders, but it also answers the German yearning for avoiding confrontation between the superpowers.

The immediate consequence of all this is virtually nil. The United States and Europe are going to get together on measures regarding Iran and Afghanistan. But for more distant future, there is handwriting on the wall.

The Russians, encountering no serious resistance, continue to assert themselves. The United States still gropes for a general strategy. The Europeans look around for -- and find -- excuses to be included out. They talk of bargaining with Moscow and keeping lines open and neutralization.

So the proto-crisis, while not serious in itself, carries a grave message. The climate in Europe is a climate of weakness and accomodation. In the air here in Paris and in Bonn and in London there is the smell of appeasement.