I’m old enough to remember when there was only two, and to have read “Anarchy is What States Make of It,”within a few years of its initial publication.
Each of the three also make assumptions about individuals, a level of analysis not really explored here. Some realists (Morgenthau) attribute politics to "human nature," i.e., a will to power. From this perspective, there is no difference between politics in the home or among states. Some liberals (Simon) attribute politics to the "bounded rationality" of actors. Some constructivists (Nau) attribute politics to power differences between "agents" and "subjects."
