Network Dynamics and Spatial Shifts in Civilian Targeting: A Stochastic Block Model Analysis of the Colombian Armed Conflict

In this article, we study how civilian victimization in civil war co-evolves with shifting territorial overlap among armed actors, focusing on the Colombian conflict between 1978 and 2007. We represent armed group presence and civilian targeting as bipartite municipality–actor networks and analyze municipality projection networks whose edge weights count shared armed structures. Combining topological diagnostics with Poisson stochastic block models for weighted projections, we identify a clear regime-based dynamic. Early periods exhibit localized and segmented overlap, with fragmented projections and weak coupling across municipal communities. As the conflict expands, overlap becomes corridorized and then consolidates into a highly redundant national backbone by 2000–2004, with dense cores and multiple alternative paths that distribute intermediation across several hubs. After 2004, the system contracts and thins, reducing core depth and weakening community separation, yet a giant connected component persists, producing fuzzier community boundaries. These results provide a compact and reproducible characterization of how territorial overlap in civilian targeting shifts from fragmentation, to corridor-based consolidation, to post-peak contraction.