Power-sharing is a widely recognized strategy for reaching durable settlements to civil wars with center-periphery and identity-based cleavages. However, in practice, power-sharing arrangements are often violated when one side exploits windows of opportunity for power-grabs. We examine public support for power-sharing versus power-grabbing in the context of sectarian and center-peripheral power struggles over control of local policing in Mosul, Iraq. In a survey experiment conducted with over 1000 respondents in both Mosul and Baghdad, we explore whether individuals believe that security in Mosul, in the aftermath of Islamic State (ISIS) occupation, is enhanced or reduced under varying power-sharing versus power-grabbing treatments. With respect to policing, we find that both Iraqi Sunnis in Mosul and Shia in Baghdad regard one-sided power- grabs as security-enhancing and opposing-side power-grabs as security reducing relative to joint power-sharing. Overall, our results underscore the challenges of finding common ground on power- sharing mechanisms for peacebuilding after insurgent violence.