Abstract
The study of International Relations regroups a large range of theorists who have different opinions about the way international politics are organised. Among these theorists, you can generally distinguish three main schools of thoughts, the liberals, the Marxists and the realists. They all help to seize different features of the interactions on the international level but what is noteworthy is that Realism tends to be in the dominant position in the study of international relations.
Realism is based on some key assumptions such as the fact that the nation state remains the key actor in the international system and that international politics is essentially conflictual. The international system according to realists is anarchical, which means that there are no supra-bodies above the nation states because the latter are sovereign. The concept of sovereignty refers to the ultimate source of authority in a society; the sovereign is the highest and final decision maker within a community (Hague, Harrop, 2007, 16). Consequently, here the nation state is the highest and final decision maker and according to realists, there are no international institutions questioning its sovereignty. Unlike liberals, realists are pessimistic concerning the establishment of moral principles that justify that the nation state surrenders a part of its sovereignty to a superior body.
