Once socialism replaces capitalism, reason will determine the policies of states. - Kenneth Waltz

Differences in the incidence of destruction and "death" do not account for the reluctance to refer to international politics as a harmonious realm, while competitive economies are often so described. Instead, one may say that the standards of performance now applied to international political systems are higher, or at least widely different. As John Maynard Keynes once remarked, those who believe that unhampered processes of natural selection lead to progress do not "count the cost of the struggle" (1926, p. 37). In international politics, we often count nothing but the costs of the struggle.

The best critical consideration of the inherent weakness of a federation of states in which the law of the federation has to be enforced on the states who are its members is contained in the Federalist Papers.

I am not saying that such a theory cannot be constructed, but only that I cannot see how to do it in any way that might be useful. The decisive point, anyway, is that a macrotheory of international politics would lack the practical implications of macroeconomic theory. National governments can manipulate system-wide economic variables. No agencies with comparable capabilities exist internationally. Who would act on the possibilities of adjustment that a macrotheory of international politics might reveal?