No Reverse Gear, Please; Blair relishes being a passionate advocate of Europe to his wary countrymen.(Cover Story)

Byline: Andrew Moravcsik, Moravcsik is director of the European Union Program at Harvard University.

Fifteen years after the fall of the Berlin wall, Enlargement Day is coming. This being Europe, there is diversity in how to celebrate. Slovenia will station traditional accordion players at its border crossings. Sweden is organizing environmental hearings. Spain has invited foreign ambassadors to make a pilgrimage to legendary Santiago de Compostela. From Scotland to Cyprus, bands will play and fireworks blaze.

But what sort of Europe is it, precisely, that the 10 new members are joining? Here, there's less to celebrate. It is a Europe where governments have lost control of the politics of integration. Consider the new European Constitution, soon to be completed and presented for ratification. Last week British Prime Minister Tony Blair, a man who famously quipped that he "had no reverse gear," proved just the opposite. After long insisting that no referendum would be required for approval by Britain, he called on Tuesday for just that--a popular vote, to be held in about a year.

Domestically, it's a clever tactic. At a stroke, Blair stations himself and the Labour Party firmly on the side of "democracy"--as unassailable a political ideal as queen or country. He has divided the Conservative opposition and pulled the rhetorical rug out from under its plan to campaign on a demand for the public's say on the matter. And clearly, the threat that British voters might reject the Constitution will strengthen his bargaining position at final negotiations in Brussels.

For Blair personally, a constitutional referendum has the virtue of shifting public debate away from Iraq and the Middle East. Blair's once unmatched prestige and popularity have eroded precariously; insiders say he had little choice but to gamble. Certainly in announcing the referendum before Parliament, Blair sounded relieved. He openly relishes the opportunity to go on the offensive, exploit his skills as the greatest communicator in modern British history and be a passionate advocate of Europe to his notoriously wary countrymen.

The question is whether Blair can pull it off, and if not, whether he will have dealt the ideal of "Europe" a grievous blow. It will be a hard sell. Euro-enthusiasts siding with Blair wax optimistic about staging a grand debate: Britain, in or out of Europe? (And make no mistake: the referendum on the Constitution will also be a vote on joining the euro.) The British public, they ...