The terrorists who have succeeded in carrying out spectacular attacks against Western targets in the past have been college-educated, technically proficient men who are capable of manufacturing and deploying chemical, radiological, and biological weapons. Al Qaeda attracts the kind of highly educated men who one day might be able to pull off such an attack.
Most people give up just when they're about to achieve success. They quit on the one yard line. They give up at the last minute of the game one foot from a winning touchdown.