This article examines how commerce promotes peace between states. It diverges from the commercial peace literature and its predominant focus on international trade by looking inside the domestic economy to see how its structure influences conflict. Drawing on selectorate theory, I argue that substantial quantities of public property generate fiscal autonomy for governments, strengthen their hold on the domestic reigns of power, and create opportunities to pursue more aggressive foreign policies. A series of statistical tests shows that greater quantities of publicly held assets increase the likelihood that a state will participate in military conflict. Given that the predominance of privately held property is one of the defining institutions of capitalism, these results support the claim that capitalism promotes peace.