The E.U.'s rapid enlargement to the east and south has further sapped it of life. Absent the cozy feel the smaller union had before the Berlin Wall came down, its original members have turned inward. The newer members from Central Europe, who have enjoyed full sovereignty only since communism's collapse, are not keen to give it away. As Poland's late president, Lech Kaczynski, put it soon after taking office in 2005, "What interests the Poles is the future of Poland and not that of the E.U."

European participation in the wars in Iraq and Afghanistan has added to the weariness. In Germany, roughly two-thirds of the public opposes having German troops in Afghanistan -- not good news for an E.U. intended to project a united voice on the global stage. Although giving Europe more geopolitical heft is one of the union's raisons d'être, this task has no constituency; these distant wars, coupled with plunging defense expenditures mainly due to the economic downturn, are tempering the appetite for new burdens.

"The E.U. is now just trying to keep the machine going," a member of the European Parliament told me recently. "The hope is to buy enough time for new leaders to emerge who will reclaim the project."

Buying time may be the best the E.U. can do for now, but its slide is poised to continue, with costs even for those outside Europe. The Obama administration has already expressed frustration with an E.U. whose geopolitical profile is waning. As Defense Secretary Robert Gates complained in February to a gathering of NATO officials, "The demilitarization of Europe -- where large swaths of the general public and political class are averse to military force and the risks that go with it -- has gone from a blessing in the 20th century to an impediment to achieving real security and lasting peace in the 21st." As the United States tries to dig itself out of debt and give its armed forces a breather, it will increasingly judge its allies by what they bring to the table. In Europe's case, the offering is small and shrinking.

Europe is hardly headed back to war; its nations have lost their taste for armed rivalries. Instead, less dramatically but no less definitively, European politics will become less European and more national, until the E.U. becomes a union in name only. This may seem no great loss to some, but in a world that sorely needs the E.U.'s aggregate will, wealth and muscle, a fragmented and introverted Europe would constitute a historical setback.

Six decades ago, Jean Monnet, Robert Schuman and Konrad Adenauer were Europe's founding fathers. Today, the E.U. needs a new generation of leaders who can breathe life into a project that is perilously close to expiring. For now, they are nowhere to be found.

ckupchan@cfr.org

Charles Kupchan is a professor of international affairs at Georgetown University and a senior fellow at the Council on Foreign Relations. He is the author of "How Enemies Become Friends: The Sources of Stable Peace."