JOURNAL: More Evidence of Diminishing Returns from Terrorism

Traditional blood and guts terrorism suffers from diminishing returns. Essentially, the public/media becomes desensitized to it and in order for it to remain effective (and continue to build the brand for the group), each subsequent attack needs to be more spectacular than previous attacks (read: "Terrorist Death-March", my more expansive 2004 brief on the topic). Some additional evidence that this was a factor in the planning of subsequent attacks on the US (and not some vague notion of deterrence as the article this is drawn from claims):

George J. Tenet, the former director of the Central Intelligence Agency, wrote in his autobiography that the authorities were concerned that Qaeda operatives had made plans in 2003 to attack the New York City subway using cyanide devices. Mr. Zawahri reportedly called off the plot because he feared that it “was not sufficiently inspiring to serve Al Qaeda’s ambitions,” and would be viewed as a pale, even humiliating, follow-up to the 9/11 attacks.