NEWS ANALYSIS : President Confounds Skeptics With His Determined Pursuit of U.S. Trade Goals : Diplomacy: He had promised to make liberalization his No.1 priority. But his tough stance has been a surprise.

When President Bush declared last month that reinvigorating the stalled global trade-liberalization talks would be his No. 1 priority at this week’s economic summit, he drew yawns and snickers around the world.

Traditionally, Presidents have cared only about “big picture” political issues such as the environment and aid to the Soviet Union. Few have been willing to spend much personal capital on resolving murky trade disputes. Efforts to deal with such esoteric matters as trade barriers--especially on a subject as remote from most voters as agriculture--have gone by the boards.

But this week, Bush is pursuing U.S. trade goals with a determination so fervent that it has surprised some of his own senior aides. Not only did he lean on West German Chancellor Helmut Kohl to back U.S. aims, but he has held unusually firm in discussions with other leaders.

As a result, the United States may well achieve much of what it wants when the seven leaders issue their communique today: an order to negotiators of the seven nations and the European Community to seek a compromise that would break the current impasse over agricultural trade and get the broader trade talks going.

“The negotiators (for the seven summit participants) are likely to be up until the wee hours of the morning haggling over language, but there’s no doubt we’ll get something that the U.S. will find acceptable,” an Administration negotiator said Tuesday afternoon before going back into his predicted all-night session. “And it’s mainly because Bush hung in there tough.”

A staffer who joined the government during the previous Administration noted that Bush’s determination on the trade issue stands in marked contrast to the performance of his predecessor, Ronald Reagan, who barely could work up an interest in trade issues.

“Reagan would have ‘digressed’ by now,” the aide said, using the polite parlance that some Reaganites used to describe the former President’s short attention span. The United States would have caved, and the Europeans would have won.

The reason for Bush’s seriousness is straightforward: The President decided months ago that achieving a successful accord in the global trade negotiations, including agriculture, was vital to U.S. economic interests. Getting real reform on trade barriers is crucial both to safeguard U.S. industry and to stave off a new wave of protectionism in Congress, the President feels.

C. Fred Bergsten, director of the Institute for International Economics, warned this week that if the talks don’t succeed, the failure will exacerbate U.S.-European trade squabbles, prod the major powers to form regional trading blocs, slow global economic growth sharply and throw financial markets into turmoil.

Congress, Bergsten predicted, would virtually declare economic war on America’s trading partners.

“You’ll not only have a Super 301,” he said, referring to a new trade law that lawmakers enacted to help punish America’s trade enemies. “You’ll have a Super-Duper 301.”

Bush has no illusions about such an outlook. At Washington’s behest, the 24-country Organization for Economic Cooperation and Development last month declared the trade talks to be its “No. 1 international economic priority,” and the summit here is expected to reaffirm that priority.

The U.S.-European dispute over agricultural trade has been the big sticking point in the global trade talks. If the rich countries don’t agree to reduce their farm subsidies, developing countries are unlikely to support the measures that the industrial countries want from the pact--protection for services and so-called intellectual property, including patents and trademarks.

That said, it is little wonder that Bush decided to take a firm stand on the agriculture issue here in Houston. The European Community’s policy-setting bureaucracy, which has been balking at U.S. demands for rapid reduction of farm subsidies, is fully represented here. But so are the heads of the individual European governments, who are split about the issue.

Bush struck pay dirt early Monday when Kohl announced that he had moved virtually all the way to Washington’s side on the farm issue, providing the first sign of a serious crack in the European front.

He acted partly out of gratitude for America’s early support for German reunification and partly to avoid the looming burden of extending the costly subsidies program to thousands of inefficient East German farmers.

Although Kohl later backed away, under pressure from EC President Jacques Delors, the damage had been done, and the EC’s solid front already had been undermined. On Tuesday morning, British Prime Minister Margaret Thatcher came in with new but still weak language of her own on reducing farm subsidies, but Bush rejected that as well, holding out for the Administration’s original mandate.

As a result, while the final communique almost certainly will contain compromise language, and the negotiators undoubtedly would still have to bargain through the night, the President seemed likely to get what he wanted.

To be sure, Bush’s tough stand on trade won’t necessarily guarantee that the global trade talks, known as the Uruguay Round, will end successfully. Lower-level negotiators from the seven summit nations and 97 other countries still must work out their differences in 15 separate categories.

But the firm stand that Bush has taken in Houston is likely to break the impasse over the farm issue and get the broader trade talks moving again, precisely the sort of “political impetus” that the Administration had hoped the summit would provide.

SUMMIT HIGHLIGHTS

Highlights of first day of Houston summit of the leaders of Britain, France, Italy, Japan, Canada, West Germany and the United States: Soviet aid: Agreed to a study of the Soviet economy before deciding on a possible Western aid package. The study, a major demand by the United States, would be concluded by the end of the year and coordinated by the International Monetary Fund. Agreed to allow any summit nation to aid the Soviets on its own.

Political statement: Political declaration pledged “practical help to those countries who choose freedom” and to loosen sanctions against China.

Talks: Negotiators met into the night on trade issues.