There is murderous anti-Americanism, and then there is anti-Americanism lite. The first is the anti-Americanism of fanatical terrorists who hate the United States—its power, its values, and its policies—and are willing to kill and to die in order to hurt the United States and its citizens. The second is the anti-Americanism of those in the United States and abroad who take to the streets and the media to rant against the country but do not seek its destruction.

Both lite anti-Americans and U.S. policymakers share the illusion that anti-Americanism that falls short of terrorism carries few concrete costs. Lite anti-Americans will tell you that they love the United States but despise its policies and that criticizing its government is indeed healthy. They are, of course, correct that in some cases the global pushback against U.S. initiatives may help inhibit the unilateral excesses, mistakes, and double standards of a superpower often driven by narrow calculations rooted in domestic politics. It is thus simplistically wrong to equate the worldwide protests against U.S. policy toward Iraq with anti-Americanism. Indeed, accusing critics of President George W. Bush’s policies of being anti-Americans—lite or otherwise—is as mistaken as branding critics of Israeli Prime Minister Ariel Sharon’s policies anti-Semites. Both accusations often simply aim to stifle what is a desirable debate in any democracy.

But lite anti-Americans are equally wrong when they assume there is no cost to their broad denunciations, especially when strident attacks against U.S. policy help stoke far deeper and more pervasive animosities and suspicions against the United States, its government, and its people. Unfortunately, it has become all too easy for those who disagree with specific U.S. policies to believe...