Agricultural policies pursed by the Unites States and the European Community have had and are likely to continue to have a dramatic impact on international ,markets for Agriculture products. And the stakes of developing countries in these policies are enormous. Thus it is only fitting that an international research institute dealing with food policy should analyze such policies. The International Food Policy Research Institute has published several studies examining aspects of developed-country actions and policies having a powerful influence on food policy environment of developing countries. These have included restrictions on entry to their own markets, the Agricultural export potential of developing countries, and the effects of European Community Policies and policy options on grain supply and prices. But, it is not enough to study the consequences of existing or possible future policies; one must also understand why policies are what they are if one wants to avoid being totally surprised by what they turn out to be in the future. This research by Michel Petit gives Particular attention to this question. It proposes a general conceptual framework based on two hypotheses: first, policies are the outcome of a dynamic process driven by conflicts of economic forces play a critical role in determining the evolution does not obey a purely economic rationality. Three case studies of U.S. and European policies and of the confrontation between the United States and the European Community permit Petit to illustrate and to enrich his conceptual framework. He adopts a research approach that we find very promising.