I was in Brussels today speaking at a conference on radicalization and jihadi terrorism. The host was the Royal Institute for International Relations, which is underwritten by the Belgian foreign ministry. The institute in recent years has taken on the alternative shorter name of the Egmont Institute, after the ornate palace where it holds its events, including today's conference. The builder and first resident of the Egmont Palace was a mid-sixteenth century Count of Egmont, who also was a legendary Flemish nationalist and warrior who met his death resisting Spanish rule. The drama of the count's life was the basis of a play by Goethe titled Egmont, for which Beethoven wrote incidental music, including the frequently performed overture. The setting of this palace was a fitting reminder of how long and extensive is the experience of people in this part of the world with threats to security and with finding ways to deal with them.

The ambassador who is head of the institute remarked to me in a private conversation that Americans seemed to him to have a “siege mentality”—a reference to U.S. responses on immigration, homeland security, aggressive counterterrorist measures and other matters. This was the observation of an official of Belgium, a country that has far more historical and geographic basis for feeling besieged than does the United States. If it wasn't the Habsburg rule that the Count of Egmont battled against, it was subjugation by the French to the south or the Dutch to the north, or Belgium being turned into a battlefield by great powers, including in the world wars of the twentieth century.

People in this part of the world, including European participants in the conference, being part of a culture that has developed amid that kind of history and is less encumbered than America by a twenty-first century siege mentality, are better able than Americans to see the downsides of that mentality and the policies that sometimes result from it. There were many references to downsides associated with the American “war on terror.” There also were reminders from European participants of how much the present-day Islamist variety of terrorism is not as different in important respects from earlier varieties, with which the Europeans also have had long experience, than Americans tend to think.

A recurring major theme of the conference was that radicalization is not to be equated with propensity to become a terrorist. The more diverse political traditions of nearly every European country in contrast with the historically more homogeneous American political culture leads Europeans to be less quick to see a security threat emerging out of every radical or alien-sounding thought. It is a difference that Louis Hartz identified half a century ago in his analysis of what he called the liberal tradition in America. It is a difference we see today in some perspectives toward the Arab Spring.

All of this is a reminder of how much America's peculiar geography and history have led to peculiar views—although Americans themselves do not tend to see them this way—of security and of interactions with the rest of the world.