By Craig S. Smith

Shortly before leaving on a recent patrol, French and German soldiers who have assumed leadership of the North Atlantic Treaty Organization's peacekeeping effort here gathered for a pep talk from France's defense minister, Michhle Alliot-Marie. "Your presence is proof that Europe exists and is capable of bringing its weight to bear on the great crises shaking our planet,'' Ms. Alliot-Marie told the troops gathered in the lush green garden of the French Embassy in Kabul.

An hour later, weighed down by steel-plated body armor, the soldiers were trudging through the dusty, sewer-scented streets on the north end of this capital, where few residents seemed to care about any distinctly European aspects of the peacekeeping mission. But Ms. Alliot-Marie's point was more that the European military presence in Afghanistan is proof to the United States that Europe exists. Or, more specifically, that the long-vaunted idea of a European defense - as distinct from NATO - is slowly taking shape.

The French and German soldiers, members of the five-nation Eurocorps, created more than a decade ago as the core of what proponents say could someday become a European army, are the most visible part of Europe's next grand project after unifying its markets under a single currency: a common European foreign policy backed up by military might.

Many American officials scoff at the idea as the lionlike dream of a military mouse, but the project has recently made significant strides: the 25-member European Union has created a European Defense Agency to coordinate purchasing and eliminate duplication among the union's militaries; it has established a command center to plan military campaigns; and it has begun training a staff for a European foreign ministry envisaged by the European Union's new constitution, which is awaiting ratification by union members.

Eurocorps took over command of NATO's peacekeeping force, known as the International Security Assistance Force, for six months beginning in August, and later this year the European Union will take over peacekeeping in Bosnia-Herzegovina from NATO altogether. Last year, the European Union relieved NATO of its smaller peacekeeping role in Macedonia and carried out its first solo military mission with a peacekeeping operation in Congo. Ms. Alliot-Marie says those operations demonstrate the ways that European defense will work as its capabilities grow: as a part of NATO, in relief of NATO and on its own without NATO.

That last option most concerns the United States, which has been eager for Europe to modernize its military capacity and yet is worried that a military-backed European political identity could someday limit Washington's freedom to act in the world. "The French government and academic world don't want to see a continuation of American power expressed in Europe through NATO," said a senior NATO official in Brussels who spoke on condition of anonymity. "Unfortunately, the French government views the E.U.-NATO relationship as a competitive one and wants to weaken NATO to build up European defense." While the United States has long wanted Europe to bear more of the NATO burden, it has worked to prevent a common European defense policy from coalescing outside NATO, warning that it would waste resources.

But many Europeans believe that, without its own defense and foreign policy, Europe is doomed to be a nonentity. "The objective is for the E.U. to have the military means to have its own ideas and interests respected the world over,'' a senior French diplomat said. The notion of a European defense grew out of the reconciliation in the 1960's between France and Germany. The countries formed a joint brigade in 1989, which was followed in 1992 by the establishment of Eurocorps, an expanded force that includes troops from Spain, Belgium and Luxembourg. But the concept took greater force with a French-British summit meeting in 1998, and the recognition that an American-led NATO response to crises affecting Europe was no longer guaranteed.

Europe had recently failed its first big post-cold-war test when it was unable to address ethnic fighting in the Balkans decisively. It took American leadership through NATO to snap Europe out of its diplomatic paralysis and intervene in the crisis. The United States emerged embittered at finding itself forced to share decision-making with an alliance that had little to add militarily. Europe, for its part, emerged chastised by its military impotence. The Balkan conflict provided the impetus for both a European Security and Defense Policy and for the American preference for action through fleeter, ad hoc coalitions.

"If there were another Balkan war today, I'm not sure we would have the same level of American involvement as before," the senior French diplomat said, arguing that Europe must be prepared to act on its own. That feeling has grown stronger as the United States reduces its military presence in Europe. Washington recently announced plans to cut American troops there, having already shrunk their numbers to about 100,000 from more than 300,000 a little more than a decade ago.

Britain, however, has acted as a brake on European ambitions. It is committed to the idea of a European defense but is loath to cross the United States or risk damaging the trans-Atlantic alliance. "The idea that there should be a European alternative equal to NATO is anathema to us," said a British official in Brussels. But the French argue that giving NATO the right of first refusal to act in a crisis makes no sense. "That's a very static view,'' said the senior French diplomat. "Who knows what the security situation will be in 15 to 20 years?''

For now, hobbled by slim defense budgets and ill-equipped militaries among most of its members, the European Union's defense operations have been small. Only a few hundred people were involved in Macedonia, and the 2,000-troop Congo operation was really a French one in European guise. The new European Union military planning capacity counts only a few dozen people, compared with thousands at NATO. Meanwhile, each of the union's 25 members has the right to veto foreign policy decisions, impeding any decisive action by Europe. "Because of the E.U.'s military weakness and lack of political direction, they cannot hope to substitute for NATO," the senior NATO official said. "There's no way the E.U. could take on a difficult mission like Kosovo."

Yet while Europe's defense institutions are fledgling and the missions it has undertaken modest, the trajectory is unmistakable. With collective defense spending of about $200 billion, Europe has the capacity to modernize its military if it acts in a coordinated way. "Just 18 months ago, European defense was a virtual structure, doing exercises on paper," the senior French diplomat said. "Now the public can see it in action and the perception is changing."

Even before its capacity is in place, the union has begun to consider expanded roles for European defense, including mutual defense - an area previously reserved for NATO. The union's new constitution includes a mutual assistance clause, though it gives NATO the right of first refusal in reacting to any attack on one of its members. Europe's proposed foreign ministry will help coordinate policies among European Union members and should reduce the kind of open rift that developed over support for the American-led war in Iraq.

While Europe may never have a clear-cut common foreign policy backed by military capacity, as individual countries do, the growing common interests of union members may well narrow the differences in their worldviews, making joint action increasingly possible. "Five or 10 years ago, European defense was 30 percent rhetoric, 30 percent ideology and 40 percent reality, said Frangois Heisbourg, director of France's Foundation for Strategic Research. "Now, because of what is happening to NATO and the U.S. footprint in Europe, we're moving toward 70 percent reality."