  As Raymond Aron and other scholars have noticed, power, the fundamental concept of Morgenthau’s realism, is ambiguous. It can be either a means or an end in politics. But if power is only a means for gaining something else, it does not define the nature of international politics in the way Morgenthau claims. It does not allow us to understand the actions of states independently from the motives and ideological preferences of their political leaders. It cannot serve as the basis for defining politics as an autonomous sphere. Morgenthau’s principles of realism are thus open to doubt. “Is this true,” Aron asks, “that states, whatever their regime, pursue the same kind of foreign policy” (597) and that the foreign policies of Napoleon or Stalin are essentially identical to those of Hitler, Louis XVI or Nicholas II, amounting to no more than the struggle for power? “If one answers yes, then the proposition is incontestable, but not very instructive” (598). Accordingly, it is useless to define actions of states by exclusive reference to power, security or national interest. International politics cannot be studied independently of the wider historical and cultural context.