"ONLY A DEMAGOGUE would say, 'Don't buy German' or 'Don't buy French,'" says Norbert Quinkert, chairman of Motorola Germany.

He's wrong. There is a middle ground between the boycotts and sanctions we impose on our enemies, and the free access to our markets that we grant to our friends. Call it transactional selectivity.

No need to rehearse at length for readers of this magazine the advantages of free trade. It permits the international specialization of labor that allows each nation to do what it does best, lowering the cost of traded goods and services, enriching both buyers and sellers. Those interested in a fuller explanation should pull out their undoubtedly dog-eared copies of Adam Smith's "Wealth of Nations."

But man does not live by GDP alone: We have other important policy objectives. True, by making it more difficult for some countries to sell their exports to us we impose costs on ourselves--in effect, a consumption tax. But the important question is whether those costs are worth bearing. Is it reasonable for us to use trade as an instrument to gain geopolitical advantages?

If America has learned anything in the past several months it is that France and Germany are intent on ensnaring us in what Robert Kagan describes as "a world governed according to the principle of multilateralism." That this effort also results in the humiliation of America, with the Security Council galleries applauding the French and the Europeans treating their onetime hero, Colin Powell, as a serial dissembler, is simply a plus for

Not that the United States is without friends--witness the courageous performance of British prime minister Tony Blair in the face of massive opposition from his own party; a letter of support from Britain and seven other European countries; and the enlistment of more than 30 countries in the "coalition of the willing" that has rallied behind President Bush and American policy. The question for America, then, is one of how to reward its friends and inflict a bit of harm on its opponents, pour encourager les autres in future encounters.

Already there are reports of spontaneous consumer boycotts of French and German products. These should be encouraged. Lest anyone underestimate the power of such boycotts, consider this. First, nothing frightens the sponsors who buy time on television networks more than the threat of consumer boycotts. They will insist on changes in programs, or drop their sponsorship completely if they think that a large number of well-organized consumers will stop buying the advertised product. Second, foreign suppliers live in dread of antagonizing their overseas customers.

A few months ago, just after Schröder had managed to get himself reelected on the back of violently anti-American rhetoric, I was asked to give a talk to the German-British Chamber of Industry and Commerce in Birmingham, a successful manufacturing center north of London. After a rather routine presentation of the state of the world's economies, I was peppered with questions by German businessmen about whether Schröder's performance would result in an American boycott of German-made goods. Representatives of Germany's car manufacturers were particularly nervous. I did nothing to relax them.