The emphasis on the role of the gang or clique is very important and has been overlooked in the past – except perhaps by those focusing on street crime.Now I'm not a psychologist, but one thing leaps out at me from Laqueur's discussion. The clique mentality described by both authors is quite similar to explanations given by soldiers in combat when discussing their acts of heroism. There is also an eerie resemblance to accounts of extraordinary efforts made by athletes in the heat of competition. Not letting down the guys seems to be a common factor in all of these and an understanding of terrorism might lie more in the realm of small group dynamics than in any broader socio/economic, political, or psychological framework.
I would fault Laqueur on one point. He seems to indicate that the gang phenomenon is a recent development spawned by the anomie of a world in which traditional categories of identification are crumbling. My own work with nineteenth-century migrant communities suggests that the problem has been around for much longer than he appreciates.