No conflict has done more to shape modern Mexico than the war between the Jalisco New Generation Cartel and the Sinaloa Cartel. It has displaced hundreds of thousands of civilians, turned entire states into contested territory, and produced levels of violence that overwhelm the capacity of both morgues and governments to respond. Yet it is rarely understood as the structured geopolitical conflict it has become. This book maps the CJNG-Sinaloa confrontation as a territorial and institutional war — examining how two organizations with fundamentally different operational philosophies compete for control of smuggling corridors, urban markets, and political protection networks. Where Sinaloa built power through negotiation and decades of embedded relationships, CJNG expanded through military aggression and media intimidation. Their collision produced not a winner, but a fragmented landscape of shifting alliances, splinter groups, and permanent instability. Drawing on conflict mapping data, judicial records, displacement statistics, and reporting from journalists operating inside the most dangerous regions of Mexico, this is a rigorous account of how criminal competition shapes civilian life — and what the cartel war reveals about the state's shrinking ability to govern its own territory.