The author uses the case study of the bombing of Osiraq to test the limits of the right of self-defense in international law. The argument that the UN Charter preserves the right of self-defense in anticipation of an attack is based on a detailed study of the legislative history of the relevant provisions of the Charter as well as on examples from subsequent state practice. The author identifies the limits of a legitimate act of anticipatory self-defense and applies the legal principles to the factual situation. The conclusion is that Israel's action was a legitimate exercise of force in international law given the particular circumstances of the case.