LONDON, JULY 7 -- President Bush deliberately bypassed routine NATO consultative channels and presented his ideas for a new defense strategy directly to political leaders shortly before this week's summit meeting here in a tactical move to assure approval by the alliance of a controversial new declaration of nuclear policy, U.S. and allied officials say.

Both the two-day North Atlantic Treaty Organization summit, billed by Washington as one of the most important in the past 45 years, and the preparations for it were tightly controlled by the president and Secretary of State James A. Baker III, who attempted to extend their characteristic style of insular decision-making to Europe.

Bush and Baker followed what has become the administration's standard approach to a major new initiative: They kept a series of ideas generated for the summit under tight secrecy in Washington by a handful of trusted senior aides and presented the ideas to the allies in a manner that diminished resistance.

In close alliance with the West Germans, they also pushed through language in the concluding communique on nuclear weapons policy that was strongly resisted by British Prime Minister Margaret Thatcher and French President Francois Mitterrand.

American officials said the results of the 16-nation summit vindicated Bush's approach, which was recommended by a special U.S. working group on NATO issues but caused much grumbling overseas. The "top-down" decision-making approach, by which much of the official bureaucracy was bypassed, followed Bush's predilections and his successful approach to last year's NATO summit, at which a proposal on reducing conventionally armed military forces was developed secretly by Washington and also presented to the allies at the last moment.

But the stakes at this summit were higher, centering on a series of new measures aimed at easing the Soviet Union's concerns about the impending unification of East and West Germany.

"Everyone knew this was to be a different summit" from past NATO gatherings, in which heads of state reiterated the doctrine of the Cold War, criticized the Soviet Union and urged new military expenditures against a common threat, a U.S. official said.

Communism had crumbled in Eastern Europe. The Warsaw Pact was disappearing and the Soviets were struggling with change. "The stage was set, the lights were dimming, and the question was what we would put on stage. . . . To ensure that it would be special, we had to take a special approach," the official said.

The official said the discussions on ways to show that NATO "must and will adapt" to the new political landscape in Europe began four months ago in a loose-knit group of roughly 20 senior officials from the departments of State and Defense, the National Security Council and the Joint Chiefs of Staff.

The group was charged with developing a U.S. strategy to deal with the rapidly changing events in Eastern Europe, including "what the mission of U.S. forces in Europe is" and how the West should proceed in arms control negotiations with members of the disintegrating Warsaw Pact, the official said. It was chaired by deputy national security adviser Robert Gates.

Bush, acting on the group's recommendation, decided three weeks ago that he would take the initiative by developing a detailed draft of the final summit communique without canvassing the Europeans.

A U.S. official said that this secret list of U.S. ideas was presented to the leaders of Germany, Britain, France and Italy just 10 days before the summit to short-circuit the traditional consultative process that produced stultifying results in past NATO communiques.

"There was never an effort to spring a surprise, but to complete a document and insert it in the political scrum rather than the bureaucratic scrum," the official said, using a rugby term to describe how the bureaucracy was bypassed in favor of a presentation at the top.

"We thought that by the time the effort was bureaucratized, it would be watered down," the official said.

Among the Bush proposals eventually adopted by NATO leaders were the elimination of short-range nuclear artillery shells from Europe if the Soviets agreed to do the same, an invitation to Soviet President Mikhail Gorbachev to address alliance leaders and the accrediting of Soviet and East European diplomats to NATO.

Bush's top advisers anticipated that the initiative likely to be most controversial overseas would be a new declaration of alliance nuclear policy. NATO would pledge under the new policy to use nuclear weapons only as a "last resort," rather than continue to stick to the more vague traditional statements that allowed their earlier use in the event of a war in Europe.

One official said they consulted closely with NATO Secretary General Manfred Woerner, a former German defense minister, both in refining the ideas and developing a strategy to win their acceptance.

The U.S. official said the statement was developed out of concern that NATO's policy of threatening to be the first to use nuclear weapons in a conventional conflict "would be a problem in Western political discussions." He said Washington was also sensitive to the Soviet view and fears that the "first use" policy is a "talisman about NATO, about its proclivity to go nuclear."

Thatcher and Mitterrand quickly expressed their concern about the proposed declaration that nuclear forces should be "truly weapons of last resort" in a European conflict.

Thatcher complained about the proposal in a letter to Bush, asserting that it could undermine NATO's deliberately ambiguous strategy of "flexible response" to any potential Soviet aggression.

British officials said that by stating, even in vague phraseology, when U.S. nuclear weapons would be used, NATO would diminish the weapons' value in deterring conventional conflict and would inadvertently promote their eventual withdrawal from the continent.

With strong support from the West German government, which is trying to quiet growing anti-nuclear sentiments, Baker pushed ahead with the proposed declaration, circulating the draft virtually intact to other NATO capitals late last week.

Aides to Thatcher and Mitterrand again raised their concerns once the summit meeting began, with the British suggesting an alternative in which nuclear armaments would be described as "weapons of war prevention" rather than of "last resort."

But Bush and Baker made it clear that while their chosen phrase would not be discarded, it could be surrounded by language that satisfied some of the British concerns.

A phrase was included in the communique stating that "there are no circumstances in which nuclear retaliation in response to military action might be discounted."

West German Chancellor Helmut Kohl, when asked which of the sentences should be believed, said the U.S. language had "a particular weight," and a senior U.S. official said the British language could be reliably ignored.