ABSTRACT
This chapter reviews contributions made by colleagues in the preceding pages. It seeks to place studies of influence in a theoretical context, referring especially to the works by Robert Dahl, Ashley Tellis, and Michael Barnett and Bud Duvall. What is meant by influence, and how do we know that an attempt to influence has had the desired or expected effect? This chapter emphasizes the need for counterfactual reasoning to provide a basis to compare what would have happened in the absence of an influence attempt on the one hand and what has actually happened after the exercise of influence on the other hand.
