Can the deaths of innocent people be justified? There is a Just War Theory of Roman philosophical and Catholic origin representing ethics of war. The main claim of this theory is that any conflict is developed with regard to philosophical, religious or political justice criteria and occurs in the result of certain conditions.The first outstanding person, who talked about ‘just under certain conditions’, was Cicero. Christian medieval theory and its supporters Augustine of Hippo and Thomas Aquinas also mentioned ‘just under certain conditions’. Another representative was Francisco de Vitoria who criticized the conquest of America by the Kingdom of Spain (Holmes 1989). Later on, Thomas Hobbes had destroyed the theory of Just War as he introduced the works on classical republicanism.Whether Christian principles or a secular foundation underlies in the Just War theory is hard to define at once. At first, let us pay our attention to the fact that one of the Catholic Church’s teachings justifies military defense in case:Thus, on the one hand, the Church doesn’t reject the possibility of war under certain circumstances for the favor of the nation. Nevertheless, secular humanists claim that universal ethics is a basis of war ethics. In one way or another, Just War theory has been developed for distinguishing between justifiable and unjustifiable uses of organized armed forces (Hoffman 2006). Nowadays the main attention is paid to the appropriateness of armed force involvement (jus ad bellum) and the level of acceptability in using such force (jus in bello). The former concern evokes a vivid discussion in the international society nowadays.Islamic ethics of war may seem to be unrealistic. It is rarely possible to find a non-Islamic individual, who justifies their strategies or military means. It is possible to give the following example: in order to resolve Iran-Iraq during Peoples IslamicConference in Mecca and Baghdad, where scientists together with Muslim activists took part, the participants came to the common conclusion.