Henry Kissinger's Comparison of Realism and Complex Interdependence Henry Kissinger was a star academic at Harvard and Secretary of State. Yet, neither he nor anyone else has written a Summa Diplomatica presenting all sides of international relations. In Power and Interdependence, Robert Keohane and Joseph Nye modify Kissinger-type "realist" interpretations of international relations. Though the "complex interdependence" they develop initially seems to be at odds with the "realism" described by Kissinger, the two can be complements from the right perspective.