THE PROCESS OF Soviet-American relations comes down to a continuing quest to draw rules to keep competition within bounds. The pursuit of rules is acknowledged in regard to strategic arms. It is tacit in regard to espionage. Both sides long ago decided to spy - but within limits. Though they surely know or suspect who most of each other's agents are, they grant them entry and let them operate - while keeping an eye on them. The two governments shy from doing physical harm to each other's agents. Political things being equal, each hesitates to embarrass the other's intelligence service by exposure.

In recent months, of course, political things have not been equal. That's why the air has been unusually full of spy charges. By the Russian version, which some American officials privately accept, the United States bent the rules last month by arresting, publicizing and holding for trial on high bail - rather than quietly expelling - two accused Russian spies. The Kremlin quietly warned that "two can play at this game." When, soon, further publicity was given to discovery of a Soviet-operated electronic listening post in the U.S. embassy in Moscow, the Russians publicly protested this "artificial aggravation" of East-West relations.In quick sequence they disclosed that they had quietly ousted an accused American spy last July, and they pulled an American businessman out of his car on a Moscow street on a reported smuggling charge. Apparently he was arrested to be exchanged for the arrested Russians; regardless, we do not think his company, International Harvester, should do normal business with the Russians until he is free.

If the United States were prepared to forego spying there, it would be in a position to crack down hard on Soviet spying here. But espionage conducted inside Russia remains an attractive and presumably useful supplement to intelligence operations carried on out-side. Experience should have shown what sort of operations - we refer to intelligence collection - have a value worth the stress and risk of conducting. If that means the Soviets will continue to enjoy enhanced opportunities to collect intelligence here, then it is the task of U.S. counterintelligence to limit the damage. There is no particular benefit, we feel, in breaking the tacit rules by which these activities go on. The rules not only regulate intelligence operations. They also prevent intelligence activities from souring the climate in which rules on more important matters are pursued.