Paris ? A combination of jet lag, a comfortable padded leather armchair in the Victor Hugo room of the French National Assembly’s annex and the droning on of one more seminar on Europe’s role in the world beckons me toward an oasis of snooze. But the jarring and unexpected sound of unpleasant reality being spoken in French halts my eyelids at mid-droop.

If present demographic trends and tight barriers against immigration remain in place, the proposed mighty new 25-nation European Union will record a net decline in population of 50 million people by 2050, parliamentarian Elisabeth Guigou is saying. The new Old Continent’s work force will be literally decimated, its economy will probably stultify.

But no gasps of horror, no sharp intakes of breath pierce my drowsiness. The discussion quickly bypasses such unpleasant facts of life to revert to abstract debate on the powers of the European Parliament vs. those of national governments.

While Americans sponsor radical change in the Middle East and fight a war against global terrorism, Europeans move deeper into a challenging but essentially inward-looking exercise of continental redefinition. Like the Sicilian aristocrats in Lampedusa’s “The Leopard,” they pursue change close to home so things will remain the same. Or so they think.

These clashing angles of ambition have carved a big ditch of discord in American-European relations. While the bitter disputes over going to war in Iraq have subsided, a fundamental trans-Atlantic argument about the nature, division and use of power in the post-9-11 world will continue to ebb and flow for years to come.

Western Europe desperately seeks to preserve and expand eastward the spectacular prosperity and social progress of the past half-century. France, Germany and other states have become status quo powers in world affairs in large part because they have much that is worth preserving yet exorbitantly expensive for their taxpayers.

The current 15-member European Union needs calm on its periphery as it launches a colossal job of social and economic re-engineering. That need is at odds with President Bush’s outward focus, and particularly with his determination to bolster U.S. security through preventive military action abroad.

This is a good if misleading moment for Eurocrats. Pride is manifest in the euro, which rides high against the dollar in its 18th month of existence. The draft European Constitution shepherded into semifinal form last week by Valery Giscard d’Estaing, the astute former president of France, is also cited as evidence of new identity-shaping and political integration.

Even the bruising campaigns by France and Germany to keep Britain and the United States from going to war in Iraq are hailed as proof that Europe will not be pushed around by a rogue Yankee hyperpower.

But over the horizon these developments create their own problems. The euro’s rise against the dollar cuts deeply into Europe’s competitiveness in world markets. Giscard’s draft constitution leaves for further debate key questions, including how a common foreign policy can be established.

The Iraq disputes have made consensus on defense and foreign policy even more difficult to achieve. To their consternation, French President Jacques Chirac and German Chancellor Gerhard Schroeder find they exist in a multipolar Europe in which official support for U.S. positions is strong.

“Against the Anglo-Spanish Atlantic axis,” writes Jacques Julliard, a columnist for Le Nouvel Observateur, France and Germany must now adopt “an organic fusion of their diplomatic and military establishments. There is no other way to save the idea of Europe, which is threatened by America’s neoimperialism.”

The Bush administration should do nothing to give such overheated rhetoric credibility. Prolonging petty retaliatory steps against France and Germany does just that. It is not up to America to divide Europe. Europe can do that on its own.

As Guigou pointed out at last week’s seminar, there are heavy costs in maintaining the status quo and disturbing long-term trends for those who would construct Europe as a global rival and counterweight to the United States.

One is negative population growth: Birth rates in major Western European countries have fallen to 1.5 children or less per woman. Legal immigration is severely restricted, largely to avoid exacerbating social tensions focused on Arab and African immigrant ghettos. Meanwhile, with higher birth rates and a flow of a million new immigrants a year, the U.S. population is growing.

After an admirable run of success, France, Germany and other nations in Western Europe face serious prospects of economic decline and social dislocation. They must simultaneously manage their weakness and the unpredictable, rising power of Bush’s America. That is nightmare enough to disturb any catnap.

— Jim Hoagland is a columnist for Washington Post Writers Group.