Ever since the U.S.-led North Atlantic Treaty Organization lost its enemy--the Soviet Union--five years ago, the 16-nation alliance has been looking for a raison d'etre. For even longer, Europe has been searching for a way to gain some military independence from its younger but bigger transatlantic brother. Last week both found what they wanted--a flexible NATO structure that enables the alliance to act as regional policeman for crises big and small, and for the first time lets the Europeans, in theory at least, lead their own missions under NATO's umbrella. "We have today launched a new NATO," Secretary-General Javier Solana declared following a meeting of the alliance's foreign ministers.

Appropriately, the allies met for the first time in the city that had been the cold war's focal point. "Berlin and NATO have made history together," declared German Foreign Minister Klaus Kinkel. But all the upbeat speeches could not mask an uneasy tension between the Europeans and the Americans over whether substance will match symbolism in Europe's supposedly greater role. "[The new structure] makes NATO a more European institution, but miraculously, it means the Americans remain the most important power," says Jonathan Eyal, director of studies at the Royal United Services Institute in London. "It does not answer any fundamental points."

U.S. officials took pains to emphasize one facet: the new military flexibility gives NATO, once designed only for repelling a massive Soviet attack, the means to handle lower-level post-cold war missions for crisis management and peacekeeping, such as the current operation in Bosnia. Any boost to Europe's military self-image "will be a bonus," an American official said.

For Europeans, that was the heart of the deal. "Europe will really be able to express its personality," says Herve de Charette, the Foreign Minister of France, which marked a return to nearly full participation in the alliance's military activities after a 30-year boycott. Many important details still need to be worked out before the next foreign ministers' meeting in December; France will be watching closely. Cautioned an official in Paris: "What happens there will affect France's decision whether to continue its reintegration into NATO."

Last week's compromise was reached only after more than two years of debate and several days of intense wrangling. The American delegation was furious with French efforts to turn the issue into a U.S.-European confrontation. The central principle is that when the Europeans want to conduct a military operation that the U.S. wants to stay out of, they can borrow NATO assets that are mainly U.S. owned, including large transport aircraft, intelligence satellites and sophisticated communications gear. Political control would then pass to the Western European Union (WEU), but the mission and equipment would have to be approved in advance by NATO--effectively handing the U.S. a veto.

Nonetheless, "this is an extraordinary departure for us to make our assets available to another institution," says a senior alliance diplomat. It marks an important shift too by the Americans. During the cold war, they paid lip service to a greater European defense role but in practice opposed moves in that direction. "We had a responsibility to manage the cold war, especially the nuclear confrontation with the Russians," explains U.S. NATO Ambassador Robert Hunter. "We didn't want the Europeans going off on their own and messing things up."

But the country that traveled furthest to reach last week's accord was France, which under De Gaulle pulled out of NATO's integrated military structure in 1966 to protest American hegemony and sought to build a separate European defense. The end of the East-West nuclear standoff devalued Paris' independent posture, and the 1991 Gulf War proved the French to be ill equipped for new regional wars and unschooled in alliance battlefield tactics because it had shunned joint exercises.

The Europeans' shamefully weak response to the crisis in the former Yugoslavia and the dismaying sight of the U.S.'s sitting on the sidelines convinced Paris that Europe needed the Americans. Crucial to the change in French thinking was the election to the Elysee last year of staunch Gaullist Jacques Chirac. The death of its European defense dream left France with no alternative to NATO, but just as it took Nixon to lead the U.S. into new ties with China, "the French rapprochement with NATO was easier for Chirac than for a non-Gaullist," says Thierry de Montbrial, director of the French Institute of International Relations.

Paris had been drifting closer to NATO for some time, but the breakthrough came last December when it announced it would rejoin the strategy-setting military committee and other planning bodies and attend meetings of defense ministers. Though France stopped short of rejoining the integrated military structure, that could happen, De Charette said last week, if NATO's restructuring continues to go in directions that the French favor.

A key part of the blueprint for the new NATO will be the addition of new members from the former Warsaw Pact countries of Eastern Europe, a prospect that has sent Russia into a fit of angry protest. Although Russian Foreign Minister Yevgeni Primakov sounded more cordial on the issue when he met with NATO counterparts last week, expansion was little discussed by the allies to avoid inflaming Russian sentiment ahead of the presidential election on June 16. Still, NATO is likely to hold a summit next spring to name the first of the new candidates for full membership.

In the meantime, officials will be working overtime to sort out the details on Europe's new NATO role, which will involve nitty-gritty operational problems and security theology, as well as domestic politics on both sides of the Atlantic. Last week's 11th-hour haggling, for instance, was over the integrity of NATO's chain of command, headed by the Supreme Allied Commander Europe (saceur), who is by convention an American general (currently George Joulwan), long a French bete noire as the symbol of U.S. dominance.

Negotiators also had to finesse the question of NATO's control over a WEU-led mission once launched. The Pentagon and the U.S. Congress would never consent to lending the keys for some of their fanciest hardware without keeping close tabs on it, yet Europe can hardly boast a robust defense role if an American general can pull the plug at any time. The solution provides for NATO monitoring, and a French Foreign Ministry official insisted that under the spirit of the accord, "there is no question of a veto in this form."

For all the Eurocelebrations, U.S. insiders maintain little has changed but lines on organizational charts. "Frankly, we're skeptical it will come to much," said a senior official. "We can't think where task forces might be deployed without the U.S. taking part" because America would not want to cede its leadership role. One candidate comes to mind: an extended mission in Bosnia. Although peace remains unsecured, the U.S. has vowed to pull out after Dec. 20, and the Europeans say they won't remain by themselves. Staying in Bosnia would be risky, but failure to act would show that Europe still depends on American muscle. As France's Le Monde put it last week, "The Europeans demanded emancipation from [the U.S.]. Now it is up to them to prove they are up to their ambitions."

--With reporting by Bruce Crumley/Paris, Barry Hillenbrand/London and Bruce van Voorst/Bonn