Since September 11, 2001, I have often wondered how, say, Frenchmen, Britons, and Swedes, would have behaved if, instead of destroying New York's World Trade Center, terrorists had killed nearly 3,000 people in attacks on the Eiffel Tower in Paris, the area around Big Ben in London or the Swedish Parliament in Stockholm. I already know how the Spaniards reacted when the terrorists kill hundreds in Madrid.

Since September 11, 2001, I have also believed that we should be very wary of European public opinion, especially when it is in its anti—American mode.
With few exceptions, Europe's elites, particularly on the left, always have been publicly contemptuous (and privately jealous) of the United States. They have always mocked our diversity, our informality, our social mobility, and our appeal to the huddled masses of the world.

Despite the fact that the U.S. saved Europe in two world wars, and left thousands of its soldiers buried in its graveyards while doing so, the intellectuals of Europe cannot forgive history for its having ceded to us in the New World the Old World's erstwhile cultural, diplomatic, economic and military dominance.

When European intellectuals and their U.S. counterparts proclaim that the peoples of the world hate the U.S., they have it backwards. Americans are not the ones who are paying fortunes of money to be smuggled into other countries. Do Europeans see Floridians rafting to Cuba in order to live under Fidel Castro? Do they see Texans crossing dangerous deserts in order to work in Mexico? Do they see Canadians spending their winters in the Sudan and Saudi Arabia, instead of  Florida, Arizona, and California?

Nothing delights Europeans more than seeking solutions acceptable to world public opinion. Yet, because of different perceptions of justice, democracy, self—determination, colonialism and imperialism, world public opinion doen't exist. It isn't based on an agreed—upon value system. It is not objective. It is hard to define. It is easily manufactured and manipulated. It is ephemeral. It has a short memory. And it can be wrong.

How should one define world public opinion on a given issue? By the level of violence committed in its name? By its repetition? By its media coverage? By the language and number of resolutions that the United Nations has adopted on the issue?

Or what about the fickle and forgetful nature of world public opinion? It condemned American intervention in Vietnam, but it ignored China's conquest of Tibet. It condemned U.S. use of nonlethal tear gas during the Vietnam War, but it maintained silence when Iraq used lethal poison gas during the Iraq—Iran War. Also, where was European public opinion when the Soviet Union invaded Hungary in 1956 and Czechoslovakia in 1968?

Clearly, when the U.S. enters something as momentous as the war on terrorism, for example, it is obliged to to  explain and, if possible, justify its actions. But when Thomas Jefferson admonished us, in the Declaration of Independence, to afford 'a decent respect to the opinions of mankind.' he did not mean blind obedience to the opinions of mankind, including the part of mankind who live in Europe.

When our national interests are involved, when there is no other choice in, say, fighting terrorism or preventing rogue states like Iran or North Korea from using weapons of mass destruction, we must do what we must do, even if that means defying the voices of so—called public opinion.

Edward Bernard Glick is a professor emeritus of political science at Temple University in Philadelphia.