The article tries first to analyse the different use of the concept of war made by George W. Bush with reference to the terrorist attack of 09/11 and to the invasion of Afghanistan. In order to do this, the paper will start from an analysis of the concept of terrorism itself and from the question whether terrorist acts can be designed as acts of war. It turns secondly to the more philosophical aspects of the question of terrorism, war and peace, starting from questions about the applicability of just war theories to the so called “war on terrorism” and discussing finally what is called “The Kantian Project”, that is the Kantian arguments for the establishment of “eternal peace” among the states of the world.