By by excellent McGill colleague, Khalid Medani:

"Political Islam and Militancy: A Political Economy Approach," Centre for Developing Areas Studies, Foresight 1, 2 (December 2007).

In order to understand the socio-economic
conditions under which recruitment into Islamist militant
organizations occurs, it is imperative to understand when
and under what conditions religious rather than other
forms of identity become politically salient in the context
of changes in local conditions. However, instead of
emphasizing aspects of Islamic doctrine, the impact of
U.S. foreign policy, or formal political and economic
linkages with nation-states, it is important for policy
analysts to focus on the informal institutions that have
resulted in the organization of Islamic militancy at the
level of the community. This is important since the bulk
of analysis on the shortcomings of the global war on
terrorism have highlighted the failure to understand the
belief systems of jihadist Muslims and Islam more
generally. Contrary to popular misconceptions, jihadists
remain a minority in Muslim countries and there is little
indication that they are winning the battle for the “soul of
Islam.” The roots of the problem are locally specific and
have more to do with political and economic crises than
doctrinal issues.