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?

p. 110 - Theory of International Politics (1979)