Washington ? President Bush went abroad last week leaving behind an administration that seemed unable to stop jabbering about its fears. In Europe, he is encountering leaders who do not talk at all about many of their deepest concerns. An embarrassed silence covers the reality that they do not have politically palatable answers to the new European conundrum.

Bush is an instinctual politician. That trait should come in handy on a trip where he must listen carefully to what is not being said as well as to the flowery speeches and programmed responses to requests for more European help for America’s war on terrorism.

This is not his father’s Europe, not Bill Clinton’s Europe, and not even the Europe that Bush visited a year ago. It is a Europe that is simultaneously expanding its borders and remembering why they were needed in the first place. It is a Europe in which politics increasingly centers on immigration, race and crime rather than on broad economic and security issues. Those issues have been effectively taken off the Old Continent’s political chessboard by the end of the Cold War and the arrival of the single euro currency.

The European conundrum is a many-edged problem shaped by declining national birth rates, culturally indigestible masses of foreign workers (and more importantly, foreign nonworkers) within their populations, dependence on the benefits of the welfare state, and a wave of lawlessness and privatized violence to the east in the realm of the former Soviet empire. These factors the human factor, in reality spark the fears that Europe’s leaders think of constantly and speak of in direct terms almost never.

Bush was in France and Italy after visits to Germany and Russia. He is no doubt getting an earful about Iraq, about America’s sabotage of the Kyoto Protocol, and about the perceived U.S. penchant for unilateral action and meaningless multilateral rhetoric. But these topics are in large part symbols chosen to convey the fears the weak inevitably have of even the well-intentioned strong.

When European politicians warn of the dangers of American mishandling of Iraq or the Israeli-Palestinian conflict, they are expressing concerns about the large Muslim minorities inside their borders and even within their constituencies. U.S. and Israeli military strikes against Arabs, however justified, threaten these politicians with riots or, perhaps, electoral defeat. Why don’t you Americans understand what we can’t say?

The broader (unspoken) question European politicians face is this: How do we maintain social peace the lack of which voters increasingly associate with immigrants and the benefits of the welfare state, which requires immigrant labor to fill the gaps created by declining European birth rates? The (unspoken) answer is to shut off immigration from the Muslim nations of North Africa and the Mediterranean and turn to Poland and other East European nations for workers in the future.

The European Union has with little public debate recently committed itself to take in a dozen new members in the next two years. “We’re not talking about whether we should expand so rapidly, because if we did, we would never do it,” says a European Union official. Fears of being overwhelmed by the unemployed or criminal gangs from Ukraine or Russia are expressed indirectly in proposals to have EU border guards help the Poles and other newcomers guard their eastern frontiers as expansion is accomplished.

Fear and borders, which are the national expression of fear stand center stage in the dawn of the 21st century. The U.S. government guards America’s frontiers with new vigor since Sept. 11. On this trip Bush is suggesting that NATO transform itself into an organization capable of defending not just European territory but also of carrying out future Afghanistan-type operations wherever they are necessary.

History shows it has a reverse gear: The optimism of the past decade when world leaders worked to erase barriers to the free flow of goods, capital and people has been vaporized in today’s more threatening international climate. On Bush’s trip, there was necessarily a vision of fence-building as well as fence-mending.

Americans need to recognize Europe’s new, partly insecurities without exaggerating the dangers they pose. Europe is not being taken over by anti-Semitic neo-Nazis; its political sensibility remains left-of-center and status quo (a trick only Europeans could pull off) even if the appeal of populist, immigrant-bashing campaigning suggests otherwise. Squaring the circle of revenues and benefits of the welfare state is still Job One on the continent for politicians of the left or right.

But it would be equally mistaken to miss the unspoken parts of the European message. Updating the trans-Atlantic relationship will require more than redefining military missions within NATO.

Jim Hoagland is a columnist for Washington Post Writers Group.