What struck me was that his view was that of MAN achieving world peace outside of the context of God. "MAN achieving world peace outside of the context of God" was one of the major themes of the tower of Babel.
As far as your friend is concerned, at a time such as this, it is exceedingly strange that that is the reaction he / she had. It is also suggestive of a person looking for reasosns when they are trying to cope with a disaster, but haven't the education, nor knowledge to know what they're talking about.
Your friend thinks like bin Laden, actually. Perhaps you should have anoher conversation with this person, and ask what he / she thinks the terrorists will do next. Most people can understand why someone would think that crashing into the Pentagon and the White House would devistate this country. They are , after all, symbols of war and power. The Twin Towers ? That's just crazy ! They symbolized what ? Greed, a nepotistic power play, and ugly architecture. That they held so many people, is a plus for a terrorist. The two fold attack allowed the fanatics to murder the most number of people possible ; that's all.