Our understanding of civil war is shot through with the spectre of quagmire, a situation that traps belligerents, compounding and entrenching war's dangers. Despite the subject's importance, its causes are obscure. A pervasive 'folk' notion that quagmire is intrinsic to certain countries or wars has foreclosed inquiry, and scholarship has failed to identify quagmire as an object of study in its own right. Schulhofer-Wohl provides the first treatment of quagmire in civil war. In a rigorous but accessible analysis, he explains how quagmire can emerge from domestic-international interactions and strategic choices. To support the argument, Schulhofer-Wohl draws upon field research on Lebanon's sixteen-year civil war, structured comparisons with civil wars in Chad and Yemen, and rigorous statistical analyses of all civil wars worldwide fought between 1944 and 2006. The results make clear that the 'folk' notion misdiagnoses quagmire and demand that we revisit policies that rest upon it. Schulhofer-Wohl demonstrates that quagmire is made, not found.