Paris ? The half-century-old effort to bring the United States of Europe into existence (under any other name and with a different political ethos and structure) seems to be swirling toward crisis proportions right on schedule. That may be why President Jacques Chirac voices such confidence about the future these days.

The 15 nations of the European Union failed in December to adopt a proposed constitutional treaty at a fractious summit that reopened bitter intra-European divisions caused by the war in Iraq and then deepened by the disregard of France and Germany for the EU financial rules. The constitutional impasse leaves the EU without an agreed way to reform its institutions when it admits 10 new members on May 1, and with personal relations among its leaders at historic lows.

“The history of Europe is a history of crises overcome,” Chirac rumbled in a baritone made deeper by a cold. “That is what will happen this time as well. We will reach agreement on the constitution by the end of this year, because we need to. You can’t manage things when you are 25 countries that are already difficult to resolve when you are 15.”

Chirac’s comment reflects an ingrained belief among officials on the Old Continent that European political integration advances only at the brink, in response to the pressure of events that focus public opinion on the need for change. Sometimes the leaders even supply those events.

“If we ever stopped to debate taking in 10 new countries with 75 million people all on one day, we would never do it,” one official explained to me two years ago. I had asked why the decision to expand into Central Europe and the Mediterranean was provoking so little official and public discussion within the European Union.

Now with only 100 or so days to go, Enlargement Day seems more than ever to be a calculated bounce into the largely unknown.

The addition of former Soviet satellites and even the Baltic ex-Soviet republics will erase the Cold War division of Europe. Enlargement will change the psychological and political character of the EU more than its economic parameters, which will continue to be formed by Germany, Britain, France, Spain and Italy. But how that change will express itself is less clear.

“Enlargement will bring different stages of economic, social and cultural evolution into the Union,” Chirac acknowledged in our conversation. “We will have to choose between moving at one speed, which would be determined by the slowest or weakest partners, or we will accept that we need a motor” or what he later termed a pioneer group, that is, “several countries than can come together and move faster, and further.”

Chirac made clear, as he has before, that the pioneer approach is his preferred solution. But in a shift that could ease American concerns, he offered a new emphasis on the importance of Britain playing a leadership role in shaping European foreign and defense policies. Chirac and German Chancellor Gerhard Schroeder will meet with Britain’s Tony Blair this month in the second tripartite summit in recent weeks.

France and Germany have insisted on being a two-power “motor” over the past year, successfully imposing their bilateral agreements on agriculture and other EU internal topics on the organization.

But that approach did not work very well on foreign affairs. France and Germany were unable to turn their strong opposition to waging war on Iraq into effective policy to deter Britain or the United States. There seems to be a new appreciation in Paris and Berlin that London’s help is vital in reaching foreign policy decisions that will be acceptable to the EU at large.

The divisions over Iraq also fed into the wrangling at the December summit, where Spain and Poland refused to accept the constitutional treaty drawn up by a yearlong convention under former French President Valery Giscard d’Estaing.

Chirac’s expectation that the draft treaty will be adopted at the summit level later this year and then submitted to each member state for individual and lengthy ratification procedures is echoed in other European capitals.

Chirac courts the dangers of answered prayers. The expanded and redesigned European Union he seeks — which will have some of the federalist touches dreamed of by Jean Monnet when he inspired the Common Market — will be more difficult for France and Germany to dominate. That will be reason enough for many Americans to hope the French president gets his way this time.

Jim Hoagland is a columnist for Washington Post Writers Group.