The Evolution of Al Qaeda’s Global Network and Al Qaeda Core’s Position Within it: A Network Analysis

http://www.terrorismanalysts.com/pt/index.php/pot/article/view/469

This paper uses graph analytics to look into the network of associations surrounding Al Qaeda over time.  They're able to show that Al Qaeda emerged as a hub bringing together groups with different ideologies in different areas, but that since Bin Laden's death, their network has fragmented back into ideologically isolated groups.