Soviet behavior was at the center of diplomatic thinking this week and most Kremlin-watchers were in agreement that it made little sense. If Moscow were waging a rational foreign policy, this is the time when, being on badder-than-ever terms with the United States, it should be chumming up to China on one side or Western Europe on the other, or both. As The Economist magazine points out, a basic rule in international politics is to ''never be on growling terms with all the other big powers at the same time.''
Moscow played host this week to West German Foreign Minister Hans-Dietrich Genscher and apparently treated him as abrasively as other recent visitors from the West - King Juan Carlos of Spain and the Italy's foreign minister.
Two weeks ago it called off, on 24 hours' notice, the first high-level Soviet mission to China in nearly 20 years. President Francois Mitterrand of France is reportedly thinking of calling off his prospective trip to Moscow, on the theory that it could produce nothing useful.
At least there is the consolation for others that when the Russian bear retreats into surly isolationism, it is unlikely to be doing anything assertive outside the cave. It is being negative rather than assertive.
Outsiders are left groping for an explanation. The White House in Washington clings to the theory that the Kremlin is trying to defeat President Reagan in the November elections. It would be to Mr. Reagan's advantage if he were perceived at home to be the object of Soviet attack.
But if the purpose were only to be anti-Reagan, the treatment would be centered on the single target, not broadcast all around. This is something more than just Soviet interference in domestic American politics. If it were just interference, one could assume that once the election was over we could all get back to normal diplomacy and resume arms control talks.
Some current Soviet deeds are, of course, aimed straight at Washington. When Soviet Defense Minister Dmitri Ustinov said that he has increased the number of missile-carrying submarines cruising off the US East Coast, he was talking straight to Washington.
But the Soviet boycott of the Olympic Games and defiant mistreatment of the Sakharov family hits out at the whole Western community.
The implication from the broad pattern of Soviet behavior is that Moscow is moving into a xenophobic phase that could last for some time and has little, if anything, to do with the American political calendar.
The surliness toward Western Europe and China supports the theory that this is not just Moscow being anti-Reagan. The Soviets in fact are not actively trying to split the US off from NATO and from its new chumminess with China.
This has at least the merit of allowing Washington to try to handle the Iran-Iraq war without Moscow's getting into the act. The immediate problem is to keep the oil flowing from the Gulf without having the war spread. But there is little Washington can do other than to encourage the NATO allies in Europe to take over and see what they can do.
President Reagan offered US military aid to the Gulf area to help protect Saudi Arabia and the Gulf sheikdoms from Iran. But the Arabs would prefer to defend themselves. The Arabs have three reasons for accepting help from almost any other country than the US.
First, US aid might tempt the Soviets to come in. Second, the value of US aid is newly in question because of the recent withdrawal from Lebanon. Third, Washington is so closely tied to Israel that any move it makes in the area is suspect.
The result is that the West Europeans have a new reason to consult with one another and think more seriously about the acting independently of Washington.
An all-European ''ready force'' would be more acceptable to the Arabs in the Gulf today than US forces are. There is no machinery for an all-European force, but if necessity is the mother of invention, we can assume that serious thinking will be given to such a step.
Gulf oil is of prime importance to Western Europe and Japan. It is of marginal interest to the US. The West Europeans and Japanese ought to start looking for ways and means of protecting their interests by their own resources.
The additional Soviet submarines off the US coast also give President Reagan some new homework. They may not increase substantially the number of Soviet warheads targeted on US cities, but they undermine Mr. Reagan's theory that the building of more American weapons will bring the Soviet Union to the negotiating table.
One thing was clear this week. Moscow is not heading toward any negotiating table with anyone.