The Just War and the Mystry of Self Defense

The theory of the Just War initiated by St. Augustine must absolutely seek peace. To avoid this being the case, two phases are defined: Jus ad Bellum; the Jus in Bello. Thus, self-defense as a just cause is a concept often addressed in international law and its explicit recognition in Article 51 of the United Nations Charter has made it even more present. But, from the adoption of the Charter to today, there are many examples of actions or arguments of states based on self-defense that are more or less in phase with each other. The most recent references to the concept of self-defense have developed in a particularly volatile international context since the attacks of September 11, 2001, and the consequences that ensued. The relationship between the just war and self-defense raises some questions: can the anti-terrorism war, the preventive war and the war against non-state actors be considered part of the principle of self-defense? What are the criteria for Jus ad Bellum and Jus in Bello considered during the Self- defense?