Firstly, Vittola discusses one of the just causes of war, most importantly, is when harm is inflicted but he does mention the harm does not lead to war, it depends on the extent or proportionality, another condition to jus ad bellum (Begby et al (2006b), Page 314). Frowe, however, argues the idea of “just cause” based on “Sovereignty” which refers to the protection of political and territorial rights, along with human rights. In contemporary view, this view is more complicated to answer, given the rise of globalisation. Similarly, it is difficult to measure proportionality, particularly in war, because not only that there is an epistemic problem in calculating, but again today’s world has developed (Frowe (2011), Page 54-6). Furthermore, Vittola argues war is necessary, not only for defensive purposes, ‘since it is lawful to resist force with force,’ but also to fight against the unjust, an offensive war, nations which are not punished for acting unjustly towards its own people or have unjustly taken land from the home nation (Begby et al (2006b), Page 310&313); to “teach its enemies a lesson,” but mainly to achieve the aim of war. This validates Aristotle’s argument: ‘there must be war for the sake of peace (Aristotle (1996), Page 187). However, Frowe argues “self-defence” has a plurality of descriptions, seen in Chapter 1, showing that self-defence cannot always justify one’s actions. Even more problematic, is the case of self-defence in war, where two conflicting views are established: The Collectivists, a whole new theory and the Individualists, the continuation of the domestic theory of self-defence (Frowe (2011), Page 9& 29-34). More importantly, Frowe refutes Vittola’s view on vengeance because firstly it empowers the punisher’s authority, but also today’s world prevents this action between countries through legal bodies like the UN, since we have modernised into a relatively pe>