ROME — FOLLOWING the dramatic collapse of communism in Eastern Europe and the Soviet Union, leaders of the North Atlantic Treaty Organization (NATO) met in Rome last week to agree on changes to the alliance, including abandoning the decades-old military doctrine of defending Europe from a potential Soviet invasion from Central Europe."History does not allow us to stand still," said NATO Secretary-General Manfred Worner in announcing the changes. "New challenges demand new answers." The alliance's new strategy includes the creation of multinational rapid-reaction forces, aimed at protecting member states from regional conflicts; the reduction of conventional and nuclear forces (about 80 percent of NATO's tactical weapons will be eliminated); and a greater emphasis on dialogue, cooperation, and a political approach to security. The likelihood is now "even more remote" that nuclear weapons would ever be used by member states, according to The Alliance's New Strategic Concept. Before the summit opened, some diplomats expressed doubt as to how long the United States military presence in Europe would continue, given the reduced threat from the east, the approach of political and economic union in Western Europe, and the possible upswing in US isolationism. But the Americans, the British, and the Germans, at least, worked to stress their firm support for "the Atlantic link." "Nobody wants the American troops to leave," British Foreign Secretary Douglas Hurd said in a British television interview. "Nobody wants NATO to disintegrate." A general understanding also seemed to emerge from the Nov. 7 and 8 meeting in Rome that if pan-European armed forces are created, they should complement NATO rather than replace it. In the run-up to the summit, France and Germany had announced a proposal that could lead to the development of a European army. Britain and Italy had earlier proposed an institutional bridge between NATO and the European Community (EC). "What we're anxious to avoid is duplication between NATO and any European defense entity," explains a British government source. Otherwise, he said, one might ask "Why NATO?" German Chancellor Helmut Kohl won warm praise from American and British officials after he told the German Parliament last Wednesday that creation of a European defense entity "is neither an expression of doubt of the stability of the Atlantic alliance nor an attempt to create a competing body." European Community leaders are expected to discuss the future of European defense at their summit next month in Maastricht, Netherlands. The Community, meeting here during the NATO summit, announced Friday that it was imposing economic sanctions against Yugoslavia after repeated unsuccessful diplomatic attempts to stop ethnic fighting there. Among the steps taken was suspension of the EC's trade agreement with Yugoslavia, which had previously conducted 60 percent of its trade with EC countries, and a call to the United Nations to block oil shipments to the troubled Balkan country. On Saturday, President Bush announced a US decision to adopt similar measures. The Soviet Union was also a topic of attention in Rome last week. A British government source said that, when Mr. Bush and British Prime Minister John Major met for breakfast on Thursday, they talked for "longer than anticipated" about the Soviet Union's potential inability to meet this month's payments on its foreign debt and what steps the West should take. No details emerged from the discussion. In response to East European desires to forge closer ties with NATO, the alliance invited the foreign ministers of the Soviet Union, the Baltic states, Poland, Hungary, Czechoslovakia, Bulgaria, and Romania to meet with NATO foreign ministers in Brussels on Dec. 20 to discuss political and security issues. The alliance firmly rejected the idea of any East European membership in NATO at this time.