Given the scale of the damage caused to the United States, the 9/11 attacks neither required much money to execute, nor did they take a large number of plotters. Terrorism is a cheap form of warfare--the first World Trade Center attack in 1993, for instance, only cost a few thousand dollars. This is particularly the case when you have a cadre of young men willing to engage in suicidal terrorism. According to court documents entered in the trial of Al-Qaeda's Zacarias Moussaoui, the entire 9/11 operation cost a little over $200,000, a trivial sum considering the damage it inflicted on the United States. Furthermore, no amount of money will buy you 19 young men willing to commit suicide in a terrorist operation. The pilots who flew the hijacked planes into two of the world's most famous buildings saw what they were doing as an act of worship.
The success of the attacks relied above all on the faith of the hijackers that they were doing God's will. Al-Qaeda's strength lies not in its material resources, which are relatively trivial, but in the nature of its beliefs. Unfortunately, since 9/11 we have seen the Al-Qaeda ideological virus spread widely, partly as a result of the war in Iraq. The spread of that virus can be gauged by an epidemic of suicide terrorism around the world that first spiked in 2003, and has reached unprecedented proportions in the past year from Afghanistan to Iraq to the United Kingdom to Egypt.
