People sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf.

The line argues that everyday civilian security is ultimately underwritten by the credible threat of force. “Peaceful sleep” stands for the ordinary comforts of stable society, while “rough men” evokes soldiers, police, and other agents of coercion who are willing to confront violence with violence. The quote highlights a moral and political tension: many people prefer not to think about the coercive foundations of order, yet they benefit from them. It can be read as a realist claim about state power (peace depends on deterrence) and also as a critique of complacency—an invitation to acknowledge the costs, responsibilities, and ethical ambiguities involved in delegating violence to others.