In his book "Globalized Islam," the French scholar Olivier Roy points out that today's jihadists have a lot in common with the left-wing extremists of the 1930's and 1960's. Ideologically, Islamic neofundamentalism occupies the same militant space that was once occupied by Marxism. It draws the same sorts of recruits (educated second-generation immigrants, for example), uses some of the same symbols and vilifies some of the same enemies (imperialism and capitalism).
Roy emphasizes that the jihadists are the products of globalization, and its enemies. They are detached from any specific country or culture, he says, and take up jihad because it attaches them to something. They are generally not politically active before they take up jihad. They are looking to strike a vague blow against the system and so give their lives (and deaths) shape and meaning.
This view is quite interesting and contrary to my view - posted as a comment to Sunil Laxman's post on the same topic.