Crossroads of Violence is a history of the intertwined development of the drug trade and socialist guerrilla movements in northwestern Mexico during the 1960s and 1970s. The Golden Quadrilateral, an area encompassing the states of Sonora, Chihuahua, Sinaloa, and Durango, never fully reaped the benefits of the Mexican Revolution. Both the socialist armed struggle and the drug trade offered hopeful possibilities for the region's underprivileged classes. Drawing on oral histories and declassified documents, Adela Cedillo traces the rise and fall of these guerrilla movements and criminal organizations, along with the brutal setbacks they faced as the federal government implemented a de facto state of siege. The convergence of the war against guerrilla groups-known as the Dirty War-and the War on Drugs led to the consolidation of a "parallel state": an informal partnership between elements of the national security apparatus and criminal organizations, whose shared goals were to profit from the drug trade and preserve the ruling party's hegemony. The legacy of that alliance has shaped Mexico's political life and the endless War on Drugs well into the twenty-first century.