Putnum's greatest contribution in this book, co-authored by Peter Evans and Harold Jacobson, is the ability to provide us with a more understanding of the dynamics of international negotiations. Unlike other frameworks which concentrate only on systemic level or domestic level, he provides a more coherent framework to capture the interactive between the two.

The model, in brief, describes international negotiations as two-level games involving a decision maker (chief negotiator, in Putnum's original work) who has to deal simultaneously with both international and domestic counterparts (Level I and Level II, respectively). The decision maker must deploy both synergistic strategies and reverberation to achieve best possible deals acceptable to both counterparts.

A good framework for understanding foreign policy formation/re-orientation. Those who are involved with the discipline of international relations and international politics should read, at least once in your lifetime.