RAND (an american quasi-government research organisation, I think - with an American National Security Research Division (NSRD) which "conducts research and analysis for all national security sponsors other than the U.S. Air Force and the Army.") has published a book called Networks and Netwars:The Future of Terror, Crime, and Militancy, all of which is available online - I havn't read it yet, but from the summary, it sounds interesting:
The fight for the future is not between the armies of leading states, nor are its weapons those of traditional armed forces. Rather, the combatants come from bomb-making terrorist groups like Osama bin Laden's al-Qaeda, or drug smuggling cartels like those in Colombia and Mexico. On the positive side are civil-society activists fighting for the environment, democracy and human rights. What all have in common is that they operate in small, dispersed units that can deploy anywhere, anytime to penetrate and disrupt. They all feature network forms of organization, doctrine, strategy, and technology attuned to the information age. And, from the Intifadah to the drug war, they are proving very hard to beat ".