NEWS ANALYSIS : Superpower Trust Key Ingredient in Evaluating Gains : Summit: Bush and Gorbachev polish ability to achieve harmony even amid disagreements.

Important as the Persian Gulf crisis was at Sunday’s summit here, more important still for President Bush and Soviet President Mikhail S. Gorbachev was their own ever-more-cooperative superpower relationship.

In three summits held over a little more than nine months, Gorbachev declared Sunday at the joint press conference that followed their final private session, the two leaders have increased their trust in each other.

“This is good for all of us,” he added. “Whether we want it or not, history dictates that a lot is going to depend on whether these two countries can work together.”

And so, disagree as they might--and they did, on specific questions, particularly on how long to rely on economic sanctions before turning to military force and on how closely gulf problems should be linked to other Mideast issues--Gorbachev and Bush went out of their way to avoid controversy and project an unprecedented level of harmony.

“It’s almost on the level of meeting (Margaret) Thatcher or (Helmut) Kohl,” rather than a traditional summit between leader of competing giants, said one Administration official, referring to the prime minister of Britain and the chancellor of West Germany, America’s two largest NATO allies.

The United States and the Soviet Union may not be allies, the official added, but “they’re not adversaries” any more. In Bush’s eyes, he and the Soviet leader are now “partners with shared objectives.”

That judgment confers on Gorbachev a status not given a Soviet leader since World War II and is an enormous change over a period of less than a year. It is a change both leaders attributed to a deepening personal relationship--and to a confluence of national interests that transcends disagreements on immediate policy questions.

“Common ground, in my view at least, surges ahead of these differences,” Bush said, going on to refer to their previous summits, last December and again in early June. “Our meeting in Malta had something to do with furthering that understanding. I’m convinced that our meeting in the United States, Camp David particularly, furthered that understanding.”

Gorbachev echoed that view. Had it not been for his previous meetings with Bush, the Soviet president said, “we would now be in a difficult situation facing the crisis in the Persian Gulf.”

Despite skepticism by many U.S. foreign policy experts, a emphasis on personal relationships with world leaders has been a hallmark of Bush’s approach to diplomacy, as his constant telephone calls to other heads of government during the last five weeks have illustrated.

The same emphasis appears to be important also to Gorbachev, a leader with dwindling authority at home who consistently appears more confident and relaxed on the world stage than in facing the deteriorating situation in Moscow.

Skeptics about Bush’s approach, especially many conservative foreign policy experts, argue that such heavy dependence on a personal relationship with Gorbachev could be dangerous, particularly since the Soviet leader is so embattled at home.

The last time an American president felt he had a personal understanding with the Kremlin chief, the protagonists were Franklin D. Roosevelt and Josef Stalin, the critics point out, noting how wrong Roosevelt’s optimistic expectations were that the two nations would be able to work together after World War II.

But Bush aides insist that this time the situation is different. The changes that Gorbachev has wrought in the Soviet Union, and the resulting Soviet retreat from Cold War confrontation, cannot now be reversed, they argue.

Bush defends himself against the Roosevelt analogy by insisting that behind closed doors, the two do speak “frankly” and air differences.

In front of the cameras, however, the two carefully avoid areas of friction.

Asked Sunday, for example, about his view about the withdrawal of Soviet military advisers in Iraq, Bush skirted the question, although the issue has aroused considerable ire in Congress.

“I think it would facilitate things” for the advisers to be withdrawn, he said, but he added, “that is not a major irritant.”

Asked about disagreements over the use of force against Iraq, Bush conceded “we may have a difference on that” but then declined to discuss it.

“President Gorbachev made an eloquent appeal, to which I agree, that a peaceful solution is the best,” he said. “I’ve left it open.”

And early in their press conference, when Bush strongly asserted that the Iraq crisis and the Arab-Israeli conflict “are not linked,” Gorbachev let it pass and made no effort to contradict him. Only much later in the press conference did he say that in his mind “there is a link here;” even then, he expressed his opinion briefly, without stressing the point.

During the Malta summit, officials say, the personal relationship between the two leaders remained formal, even a little stiff. Bush, after that meeting ended, expressed disappointment to his aides that he had not been able to break through Gorbachev’s reserve.