There is growing recognition that many illiberal leaders cooperate as readily through regional organizations as their liberal counterparts. Particularly in Africa, illiberal heads of state cooperate through regional integration organizations to address coups d'etat, insurgencies, and other threats to regional stability. What sustains their collaboration? I present a theory of regional cooperation driven by mutual interest in regional stability and protection for heads of state. RIOs rely on member contributions to address threats to leaders, and they elicit contributions with a combination of inducements and punishments. Repressive leaders contribute to regional security initiatives to receive protection and avoid punishment. Using original security personnel deployment data for 54 member states from Africa-based RIOs, I present results of two statistical tests. First, I find that repressive leaders who are likely to need security assistance were more likely to deploy personnel to support co-members between 1990 and 2015. In a second test at the directed dyad-RIO-year level, I find evidence for the underlying mechanism that leaders contribute because they expect to receive security assistance from RIO members if they do so. Leaders who previously contributed personnel to co-members were more likely to receive military support from co-members in the future. Non-contributors were significantly more likely to be targeted by co-members for anti-government military interventions. Turning to qualitative evidence, including under-utilized Nigerian archival documents, I assess whether theorized causal mechanisms were operative in the Economic Community of West African States' responses to 17 political and security crises. I find that in the preponderance of crises, whether a leader was in good standing with co-members weighed heavily on ECOWAS co-members' deliberations about whether to initiate pro-government or anti-government interventions. These findings shed light on dynamics sustaining illiberal international cooperation.