Ever since 11 September 2001 people in the West have been searching for “moderate Islam.” A couple of days ago I briefly mentioned Akbar S. Ahmed’s book, Islam Under Siege: Living Dangerously in a Post-Honor World, with particular reference to his revival of Ibn Khaldun’s concept of asabiyya. Ahmed strikes me as one any but the most Islamophoic would consider a moderate.
Ahmed believes that features of modernity, globalization and urbanization in particular, have put a strain on Islam. While existing in traditional societies, the families, clans and tribes were held together by asabiyya. Now that these social entities are being torn asunder, some among them feel the need to re-assert the cohesion of asabiyya, what Ahmed calls hyper-asabiyya. It is this paranoid and frenetic quest for a lost cohesion, that results in extremism and terrorism.
Some have observed the similarity between asabiyya and what modern scholars call social capital. Bowling Alone by Robert Putnam, has been my main source for learning about social capital. He identifies two types of social capital. Bonding social capital, akin to asabiyya, is an agent of social cohesion. It is the glue that holds a community together. Bridging social capital, working outward instead of inward, seeks out connections with other groups or to draw outsiders in.
Here in the USA, when we hear people complaining about how illegal immigrants (or immigrants in general) are diluting the sense of what it means to be an American, we are hearing an assertion that bonding social capital is lacking, or rather, that it is breaking down on a national level in favor of ethnic expressions. What is it that makes me an American? I don’t care, I’m a hispanic/white/black/turkish/italian – that’s enough for my identity. The next step, that would take us in the direction of the break down Ahmed sees, we in those who feel utterly alone. Perhaps through something like hyper-asabiyya they turn to gangs for their sense of identity.
What I see lacking in the segments of Muslim culture where hyper-asabiyya reigns (and no, I’m not an expert on Muslim culture, so correct me if I’m wrong), is bonding social capital worked to the exclusion on bridging social capital. A moderate Islam – like, perhaps, a moderate Americanism – would be concerned not only for in-group health and cohesion, but would see that health partly consisting in relationships with outsiders. Even when there is fear and fragmentation, making room for the outward focus of bridging social capital would help break down the harshness of hyper-asabiyya.
Bandits No More 
I think your point is illustrated by the difficulty Western intelligence has in infiltrating some Islamic terror organizations. I have heard it stated that some of these groups only trust people they personally know — such as brothers or childhood friends — therefore, it is impossible to infiltrate the group. While this may be efficient in blocking access by those with ulterior motives, the only influence such groups can have is through intimidation and terror, because no one else is afforded any trust … there are no social relationships through which the ideology can be passed to “outsiders.”
I suppose this is a good explanation for why violence is so prominent in the Islamic world. There is no concept of bridging social capital, but co-existing with the exclusive reliance on bonding capital is a mandate to proselytize. Proselytizing without bridging capital = conversion by force and/or intimidation.