Capitalist peace theory (CPT) has gained considerable attention in international relations theory and the conflict literature. Its proponents maintain that a capitalist organization of an economy pacifies states internally and externally. They portray CPT either as a complement to or a substitute for other liberal explanations, such as the democratic peace thesis, but disagree about the facet of capitalism that is supposed to reduce the risk of political violence. Key contributions have identified three main drivers of the capitalist peace phenomenon: the fiscal constraints that a laissez-faire regimen puts on potentially aggressive governments, the mollifying norms that a capitalist organization creates, and the increased ability of capitalist governments to signal their intentions effectively in a confrontation with an adversary. CPT should be based on a narrow definition of capitalism and should scrutinize motives and constraints of the main actors more deeply. Future contributions to the CPT literature should pay close attention to classic theories of capitalism, which all considered individual risk taking and the dramatic changes between booms and busts to be key constitutive features of this form of economic governance. Finally, empirical tests of the proposed causal mechanism should rely on data sets in which capitalists appear as actors and not as “structures.” If the literature takes these objections seriously, CPT could establish itself as central theory of peace and war in two respects: First, it could serve as an antidote to “critical” approaches on the far left or far right that see in capitalism a source of conflict rather than of peace. Second, it could become an important complement to commercial liberalism that stresses the external openness rather than the internal freedoms as an economic cause of peace and that particularly sees trade and foreign direct investment as pacifying forces.