There is a historical tension between state sovereignty, which stresses the link between sovereign authority and a defined territory, and national sovereignty, which emphasizes a link between sovereignty and a defined population. These fundamentally differ in the source of their legitimation, thereby altering the environment through which states interact. Should the state emphasis predominate, international borders will be seen as territorially determined. Should the nationalist emphasis predominate, the international community will see states as tied to specifically defined populations and as territorially malleable. The legitimacy of the nation-state in a particular era is determined largely by the principles around which the winning coalition unites during a great war. These principles cannot be objectively deduced from the nature of the states or the structure of the system, but must be induced from two variables: the political dynamics of the coalition-building process and the intersubjective consensus among coalition members as to the war's cause. Consequently, sovereignty should be viewed as a variable rather than as a constant.