Since the origins of the economic science, economists have dealt with war and peace issues. But these thoughts have generally been spread all along their works and only few book have been entirely devoted to these themes. The great diversity of economists analyses of defense, war and peace therefore calls for a kind of classification. Now, it is possible to distinguish three main approaches in the history of the economic thought, which have lasted until today: - Developments around the theme of the pacifying economy ; - Theories studying the link between foreign policy and economic policy issues ; - Analyses of capitalism as a specific system in which militarism exerts a specific role on social relations.