In the twenty-first century, going to war entails not merely strategic calculations but normative ones as well. Norms of international society have changed sufficiently in the past few decades, and especially since the 1990s, to compel states and coalitions to justify decisions to go to war with reference to concerns such as peace, disarmament, justice, and, above all, international (as opposed to national) security. Simple raisons d'état calculations, even if the primary driving force behind such decisions, are no longer considered politically and morally sufficient.
This does not mean that the principal factors determining a decision to go to war have changed radically. At the broadest level, such decisions continue to be based on decision-makers' perceptions of how "national interest" will be advanced or retarded. While this is true in the abstract, it is widely acknowledged in the decision-making literature that in actual practice, and when the decision-making process is disaggregated, "national interest" boils down to the relative strengths of domestic coalitions for and against war, the level of engagement of important interest groups, the bureaucratic politics surrounding decisions of war and peace, and the top decision-makers' concern for their (and their state's) credibility in the eyes of friends and adversaries.
In the current context, however, when international norms require that war-making decisions be justified before international opinion, such essentially realist considerations usually have to be dressed up in moral garb in order to assuage skeptics, silence critics, and provide emotional comfort both to the governmental decision-makers and to the leaders of the community of states, who may have to endorse such decisions or at least live with their consequences. Normative justifications of decisions to go to war have, therefore, become routine since the end of the Cold War.
While one is tempted to dismiss this exercise as a charade, it goes beyond mere pretense. Normative justifications that go beyond raisons d'état calculations, when resorted to repeatedly, lead to the emergence and consolidation of a range of international expectations. In turn, they begin to change the normative framework within which states operate. This does not mean that strategic calculations become irrelevant. Wars are fought above all for strategic reasons. However, the normative and the strategic become closely intertwined. As a