<a href="http://economist.com">The Economist</a> argues in <a href="http://economist.com/opinion/displayStory.cfm?Story_ID=788407">an opinion piece</a> that regardless of the many ways in which the U.S. may have angered other countries, factions, religions and peoples, nothing it did could possibly explain an attack of such viciousness. <span class="quote"><q>America defends its interests, sometimes skilfully, sometimes clumsily, just as other countries do. Since power, like nature, abhors a vacuum, it steps into places where disorder reigns. On the whole, it should do so more, not less, often. Of all the great powers in history, it is probably the least territorial, the most idealistic. ... Those who criticise America's leadership of the world's capitalist system—a far from perfect affair—should remember that it has brought more wealth and better living standards to more people than any other in history.</q></span> I agree that this attack was completely unpardonable. And, on the face of it, it is hard to rationalize how it could have been incited. But the list of foreign policy actions from the article would make even a completely rational person angry. Reacting in a complete innappropriate way is not only the purview of fanatics, it's practically a definition. So, while those reasons would never make <i>me</i> fly a plane into a building, people with a lot less to lose, who are a whole lot easier to anger and a whole lot harder to calm down might not think it's such a bad idea.