Since the end of the Cold War and with the Global War on Terrorism, armed forces have had to adapt their recruitment to the needs of peace-enforcing missions. While the human costs of these missions in terms of soldier and civilian casualties is large, very little is known about how soldiers recruited under different systems perform. Denmark has a mixed system of conscription and volunteering for military service, and this variation, together with information on soldier and unit performance while deployed, makes Denmark uniquely informative. To estimate the causal relationship between recruitment system and soldier and squad effectiveness, we use econometric methods. Although eventual deployment is voluntary, the military recruitment draft lottery identifies initial conscripts from volunteers, and the quasi-random variation of events during missions identifies effects of squad composition.