Organizational Bricolage and Insurgent Group Effectiveness in Cities: The Formation and Initial Urban Campaign of the Movement of the 19th of April in Colombia (1973–1980)

s How do rebel groups form in cities? What makes urban-based insurgent organizations effective? Urban armed conflicts have become an important subject of research due to the political, economic, and demographic significance of cities. Yet, we know little about the mechanisms of insurgent group formation and effectiveness in urban contexts. Building on the case of the formation and initial urban campaign of M-19 in Colombia (1973–1980), this article argues that rebel leaders originating from multiple organizations and confronted with intramovement competition have strong motives to employ organizational bricolage to form their organization. Organizational bricolage shapes insurgent effectiveness by producing structures that are fit for achieving certain objectives but not others. M-19’s organizational bricolage combined the armed vanguard, intellectual collective, and populist party forms. This structure was effective to foster public support but ineffective to establish a robust social base and maintain urban operations under repression. The research employs the analysis of organizational repertoires and process tracing to retrace M-19’s formation and initial urban campaign. Empirical material includes an original dataset comprising M-19 founders’ biographical data, archival documents, and interviews with ex-combatants. Studying how rebel leaders employ organizational bricolage sheds light on how insurgent organizations form, behave, and transform after war.