Temporal Dynamics in Covert Networks: A Case Study of the Structure behind the Paris and Brussels Attacks

This paper analyzes the network behind the Paris and Brussels attacks and related plots that were organized in the name of Islamic State. It answers the questions how the network was structured and how it developed over time. The database used contains highly reliable information from the judiciary and the intelligence community. It is therefore among the first to allow for statistical analysis of the typology of a covert network, while also being reliable and detailed enough to admit for an analysis of the covert network chronological development. The findings are that the network was centralized and thus vulnerable to targeted attacks against the most central nodes. The network developed in three phases: (1) construction of local cells, predominantly based on pre-existing ties; (2) travel to Islamic State and merger with a larger network; (3) consolidation before carrying out an attack. In addition, it is found that (1) most network analyses of covert networks understate the importance of peripheral nodes, and (2) that analyzing the final configuration of the network alone does not necessarily lead to correct conclusions, as it ignores the underlying structures of pre-existing networks.