When then-Secretary of State Warren Christopher inaugurated the rebuilt Sarajevo airport in August 1996, it seemed entirely natural that America's top diplomat had flown halfway around the world to preside at ceremonies marking the symbolic renewal of war-torn Bosnia.

When the reconstruction of Kosovo is complete, however, it will be a European official who cuts the ribbon.

The United States dominated the military action against Yugoslavia, but there is near-universal agreement that European nations will pay most of the cost of rebuilding the Serbian province.

And in sharp contrast to Bosnia, whose reconstruction was largely American-designed, Europe wants to bring the Balkan region into its own sphere. If Europe is going to pay, the thinking goes, it also is going to make the decisions.

Ambitious and as yet unspecific, the goal represents a radical departure: in perhaps 10 years' time, it could allow such countries as Macedonia, Albania and even Yugoslavia to join the richest club in the world, the European Union. If the goal is met, it would both transform the Balkans and mark a new willingness of the wealthier part of Europe to embrace its poorer neighbors.

After years of complaining that the United States interferes in European affairs -- but then turning to U.S. military power to resolve conflicts -- European nations in the last few months have decided to shoulder the burden of peacetime Kosovo more or less alone.

"From now on, all countries of southeastern Europe -- including the Federal Republic of Yugoslavia -- should be anchored into an integrated Europe," German Foreign Minister Joschka Fischer said this week. "Europe is the only perspective that offers a real chance of reconciliation and enduring peace to the ethnic groups of the region."

The European Union, with a population and a combined economy comparable to those of the United States, always has had the resources for such enterprises. The EU's expansion to the Balkans would extend a process that already has brought in the more developed Eastern European countries Poland, Hungary and the Czech Republic.

But Europe's determination to assume financial and political responsibility for the Balkans is an assumption of authority unprecedented in the EU's 42-year history. Until recently, European leaders have vacillated and disagreed on key foreign policy issues. The huge EU free-trade zone had created a united economy, but never agreement, for instance, on what policy to pursue in Bosnia.

One sign of how that is changing came this week when, during a two-day meeting, EU leaders agreed to create a joint defense force, appointed a foreign policy czar and took over the rebuilding of the Balkans. On Sunday, Europeans will elect a newly strengthened Parliament that some hope will lead to the creation of a single, federal Europe.

"Maybe we will say tomorrow that Europe was born in 1999," said an editorial in today's Le Monde newspaper. "For this year, several months from the end of the millennium, Europe has finally become the future collective of the nations and the peoples that compose it."

The reconstruction of Kosovo has been likened to the Marshall Plan. Indeed, the plan to repair the devastation caused by World War II in Europe was a huge investment of money, but it also brought formerly warring nations together. This fledgling effort is designed to do the same.

"For the United States, this is kind of a foreign policy job. You do it and then you go home. For Europe, there is no exit strategy. These countries must be part of Europe," said Michael Emerson, senior research fellow at the Centre for European Policy Studies in Brussels.

The extent of the rebuilding necessary in Kosovo won't be known until peacekeeping forces secure the province; some officials say the bill could be $1 billion a year for several years. European Commission President Romano Prodi has put the cost of all aid to the region -- including aid to induce neighboring countries to enact Western-style economic reforms -- at as much as $5 billion a year for six years.

Though the figures sound large, they are not that significant compared with the budgets of the countries and organizations that are participating. The European Union budget, for instance, is $100 billion per year, including funds for aid to countries on the periphery of the EU.

Peace will cost more than war. The bombing campaign against Yugoslavia cost between $2.5 billion and $4 billion, according to defense analysts. The United States paid the largest share by far, between $1.8 billion and $3 billion. These expenses do not include the cost of the peacekeeping force now entering Kosovo.

The immediate need will be to secure housing for returning refugees whose houses have been destroyed, to provide heat and electricity to those houses and to repair the infrastructure of roads and rail. By some estimates, Kosovo is more damaged than was Bosnia.

"What is in place is a broken infrastructure, a broken economy, no health system, no education system, no law and order, no civilization," said Rory O'Sullivan, the World Bank's special representative for Balkan reconstruction. "Everything has to be done."

The hope is that the refugees themselves will do much of the housing reconstruction. In a culture in which many people build their own houses, officials say they hope that plastic sheeting and roof materials will allow returning families to live in at least one room of their destroyed homes while they rebuild the rest. Aid officials are beginning to look for supply sources for those materials.

Europe's enthusiastic embrace of Kosovo reconstruction has failed to resolve a central problem, however. While Yugoslav President Slobodan Milosevic remains in power, countries and agencies will not provide aid to Serbia, Yugoslavia's dominant republic.

The World Bank will not lend money until Yugoslavia pays back the $1.5 billion it owes to international lenders. Ways can be found in the short term to funnel aid into Kosovo, but the ambitious plan to bring the Balkans into Europe will founder if one of the Balkan countries remains a pariah in the West.

"While Milosevic is in charge, there is no question of giving aid to Serbia. But how can we deal with the problem on the regional level if we leave Serbia aside?" asked Yves-Thibault de Silguy, EU commissioner for monetary and economic affairs. "There is a real political problem that I think will hamper the process of financing the reconstruction."

Staff writer Bradley Graham in Washington contributed to this report.

CAPTION: Boys walk in front of a building reportedly destroyed by NATO airstrikes in Pristina, the capital of Kosovo.