In its attitude toward the Soviet Union, the Reagan administration has shifted from confrontation toward compromise . . . and then back again.
Today, on the eve of new arms control negotiations with the Soviets, which open June 29, the mood in Washington seems to be more confrontational than anything else.
* Last week, in a speech at the United Nations, President Reagan harshly criticized the Soviets for ''aggression'' around the world, declaring that they had eroded the confidence needed for arms control.
* The next day, the President, ignoring objections from key European allies, ordered new trade sanctions against the Soviets that would delay construction of the Soviets' projected gas pipeline to Western Europe.
* And, on June 19, Secretary of State Alexander M. Haig Jr. accused Moscow of conducting a series of nuclear weapons tests, which, he said, cast doubt on the Soviet pledge not to be first to use such weapons.
The decision on the pipeline showed more clearly than anything else that the tug of war among advisers to President Reagan over how he should deal with the Soviets is far from over. In making this decision, under which a ban on the sale of American oil and gas equipment to the Soviets would be expanded to include overseas outlets and subsidiaries of US companies, the President leaned toward advisers who have been pushing for hard-line restrictions on trade with the Soviets. Among those advisers is Secretary of Defense Caspar W. Weinberger.
Secretary of State Haig has favored a policy more attuned to the needs of key West European allies. The West Europeans, most notably the West Germans, have gained considerable economic benefit from trade with the Soviets and want to preserve some vestiges of East-West detente.
During his recent 10-day trip to Europe, President Reagan gave the impression that he was growing more sensitive to West European opinion and leaning toward Secretary Haig's advocacy of ''Europe first'' when it came to foreign policy and arms control. Political pundits quickly drew the conclusion that Haig was up and Weinberger down.
Inside the administration itself, however, some officials who support Haig warn that the tug of war was far from over, and that Haig himself is the target of ''guerrilla'' attacks from other officials. These officials give as an example the debate within the administration over how far the next nuclear arms control agreement should go in restricting throw weight, or the total payload of nuclear missiles.
In his address of May 9 on arms control at Eureka College, in Eureka, Ill., President Reagan leaned toward the policy advocated by Secretary Haig, which is to place the emphasis in a first phase of negotiations with the Soviets on reducing the number of missile warheads held by the two sides. The more complicated question of throw weight would be dealt with only in a second phase. Defense Department officials had favored giving the throw-weight question more prominence and tightly linking the two phases. The issue is not yet settled as far as they are concerned, and debate continues.
In the meantime, the administration's emphasis in recent days on hard-line rhetoric -- and actions -- does not necessarily mean a swing all the way back to where it stood when it first took power 17 months ago. In his first days in office, President Reagan had indicated that he would refuse to enter strategic arms control negotiations with the Soviets if they failed to show restraint in their actions overseas. But Soviet involvement in Poland, while resulting in a delay in the start of strategic arms talks, did not put an end to such negotiations. Even as he accused the Soviets of committing ''aggression'' around the world, the President was preparing to send negotiators to Geneva to meet with the Soviets, starting June 29, to discuss strategic arms reductions.
Certainly the administration's recent choice of words stops short of the hard-line tone of the early post-election period, when President Reagan declared , at a press conference, that the Soviet leaders had reserved to themselves ''the right to commit any crime, to lie, to cheat.'' The administration now tends to use more diplomatic language than this and is mixing its criticisms of the Soviets with calls for a more constructive US-Soviet relationship.
Some of the rhetoric used by President Reagan in his United Nations speech and by Secretary Haig in his June 19 press conference dealing with Soviet nuclear weapons tests was seen by observers here as part of an effort to reduce the propaganda advantage that the Soviets derived from their recent pledge not to be the first to use nuclear weapons.