"In the last two decades political philosophers and international relations (henceforth IR) scholars have widely debated the so called “democratic peace” thesis, i.e. the idea that liberal democracies are more pacific than authoritarian regimes. The history of the last two centuries suggests that democracies have never fought wars against each other (although they have often waged wars against authoritarian states). The democratic states – this is the core of the thesis – have constituted a kind of “separate peace”. The root of this thesis is to be found in the Kantian essay To Perpetual Peace (1795). Kant believed that peace is secure only if the citizens’ interest in avoiding the atrocities of war will influence the foreign policy of their government. And this clearly happens only if the government represents the people’s will. With a series of famous articles published from 1983 to 1986 Michael Doyle has placed Kant’s intuition back to the center of the international debate. The jointly Kantian-Doyleian thesis has been subject to a series of criticisms, arising mainly, but not only from the realist school. The proposed project intends to assess critically the debate, to select the most promising variations to the original Kantian-Doyleian Thesis, and to test the validity of the whole approach against the experience of the war in Iraq."