A word to the wise: If you have a theory and want it to spread far and wide, call it “realism.”  Who could be against realism?  Case in point: The so-called “realist” theory of international relations.  According to this view, each country acts in its own objective self-interest.  The fundamental reason for international conflict, then, is divergent national interests.  (In the economically literate version, just add transactions costs to explain why countries don’t always resolve their differences diplomatically).

To me, the interesting thing about the realist theory of IR is that it’s the national version of economists’ standard rational, selfish actor model.  While this model works well in some situations, I’ve argued at length that for individual political behavior, it’s dead wrong.  Voters’ beliefs are far from rational, and their motives are far from selfish.

If the rational, selfish actor model doesn’t even work for individual selves, it’s hard to believe it would work for entire countries.  On the other hand, though, maybe there’s a difference between group and individual behavior.  In the next two parts of this series, then, I’ll separately consider the two key planks of the realist theory of IR: The motivational assumption that each country’s goal is to maximize its national interest, and the cognitive assumption that each country acts on unbiased beliefs about how to achieve its national interest.  Stay tuned.