How would a job ad for the recruitment of rebels in a civil war read? Expectations in rebel recruitment cluster around two preferences: first, individual capacities in combat are important for the establishment of a new rebel group. Combat training and experience contributes to the group’s immediate fighting capacities in addition to the training of rebels without prior combat experience. Second, strong ideological compliance with the rebels’ cause turns into a decisive asset in asymmetric warfare—that is, for the rebels’ protracted fight against a government that typically relies on superior fighting capacities. In short, warriors are needed to establish a rebel group, while believers are required for sustained rebel action. The paper’s main argument is that these two preferences create a dilemma in rebel recruitment with respect to deserters from the government army: army deserters are particularly valuable warriors for their proven combat capacities, but they are lousy believers indicated in their very insubordination as a necessary prerequisite for switching sides. The paper establishes a novel theory on rebel recruitment drawing on the body of literature on military cohesion, side-switching, and defection in civil war. The Syrian civil war serves as an empirical plausibility probe to substantiate the paper’s broader claims. Systematic interviews with former Syrian military personnel in the refugee communities of Turkey, Jordan, and Lebanon, generate empirical evidence. Deserters from the Syrian army have been crucial in the establishment of the Free Syrian Army, which emerged as the most capable rebel group in the conflict’s early stage (late 2011 to mid-2012). Yet, such former members of the regular Syrian army have expressed criticism in the rebels’ lack of professionalism and ideological direction, resulting in their compromised loyalty to the rebel group.