The tit-for-tat game of reprisals currently being played by Russia and the United States presents peculiar dangers at this time. For neither the Brezhnev regime nor the Carter regime is in strong position to control its own security apparatus, as the cops are now called.

So it is important to try to build a floor under the downward spiral in Big Two relations. In that connection, it makes sense to pay attention to a case that has been perhaps bungled - the case of the International Harvester man in Russia, F.J. Crawford.

The Crawford case began toward the end of May when two Russians - Valdik Enger and Rudolph Chernyayev, who were attached to the U.N. Secretariat - were arrested on charges of trying to buy data on this country's anti-submarine warfare program. Contrary to usual practice in Soviet spy cases, they were booked with great publicity and held on a bail of $2 million each. The unusual publicity - and maybe the steep bail - suggests that the FBI, which has not been in the best repute these days, was trying to win some rave notices.

Crawford was arrested in Moscow on June 21 in what was clearly a reprisal. The KGB showed how little it was under restraint by dragging him out of a car, and then by being confused as to wheather the charge was smuggling or illegal currency dealing. On June 26, in what looked like a bargain, the two Russians and Mr. Crawford were released to the custody of their respective embassies with the understanding they would be available for trial later.

In fact, there is no symmetry between the two cases whatsoever. The two Russians were KGB men apparently engaged in a dangerous and dirty profession. They seem to have abused the United Nations as a cover for espionage. Moscow evidently wants them back badly because the KGB takes care of its own, and the Brezhnev government is in poor posture to resist KGB pressure.

Crawford, whom I saw recently in Moscow, is a private citizen working for a reputable company that, over many years, has build up a good record in doing business with the Soviet Union. His colleagues and competitors assert his innocence, and so, after at first being suspicious, does International Harvester. Even if hs were guilty, his purely private civilian activities have nothing in common with the spook business.

That distinction needs to be made publicity and with great force. It ought, preferably, to be made by the private business community. For American business, so bold when it comes to cuffing around the Carter administration, has a vital interest in dispelling the widespread suspicion that it is chicken when the Russians crack down.

Even if the business community does not make the point, however, the U.S. government should. For not only is there so symmetry - not only can there be no trade of an American business-man for two Russian spies. More important, underlining the difference gives the president high ground to stand on in the game of tit-for-tat.

Up to now, President Carter has been largely reacting. Because he is on the defensive at home for not standing up to the communists, he has had to take retaliatory steps every time the Russians moved. Thus he felt obliged, when the trials of the dissidents Anatoly Scharansky and Alexander Ginzburg were opened two weeks ago, to cancel a scientific mission due to go to Moscow.

When the two men were sentenced, he felt obliged to cancel the sale of a giant computer to Russia and to hold up the sale of oil-drilling equipment. He was under great pressure to postpone the arms-control talks at Geneva, which in fact turned out to be quite productive.

Instead of reacting, Mr. Carter needs to force the Russians to react. The Crawford case holds out that opportunity. For the administration can tell the Russians that, while it is ready to consider trades of many prisoners, Crawford cannot be part of a bargain involving spies. Rather than give way on that point, the administration should be prepared to notify all private firms that it cannot be responsible for the safety of American businessman in Moscow, who will henceforth go at their own risk.

That threat, which the administration could easily back up, has to be taken seriously by the Russians. Making it would thus put the president in a position to hold Russia to account without endangering interest in arms control and other matters that go beyond the individuals Moscow so callously choses to hold hostage.