That rebels face a collective action problem is one of the most widely shared assumptions in the literature on civil wars. The authors argue that the collective action paradigm can be both descriptively inaccurate and analytically misleading when it comes to civil wars. They question both pillars of the paradigm as applied to the study of civil wars, namely, the free-riding incentive generated by the public goods dimension of insurgency and the risks of individual participation in insurgent collective action. The authors argue, instead, that although insurgent collective action may entail the expectation of future collective benefits, public (rather than just private) costs tend to predominate in the short term. Moreover, the costs of nonparticipation and free riding may equal or even exceed those of participation. The authors support these claims by triangulating three types of evidence: historical evidence from counterinsurgency operations in several civil wars; data from the Vietnam War's Phoenix Program; and regional evidence from the Greek Civil War. They conclude by drawing implications for the study of civil wars.