Concerning the inter-ethnic wars and conflicts that occurred in the former Federal Republic of Yugoslavia (FRY), one of the longest and most critical was the inter-ethnic conflict between the Albanians of Kosovo and the Serbs. Particularly, the most prominent humanitarian crisis that this paper will deal with refers to the period of 1998- 1999. Both; The Kosovo Liberation Army (KLA) and the Armed Forces of the government of Serbia might be classified in the ranks of “defensive realism”. The KLA was struggling to protect the Albanian civilian population from the Milosevic regime, whereas Serbia was committed to preserving and attaining its national security. In addition to this, there stands the principle of the security dilemma, since the KLA was declared a terrorist organization by the state organs at that time. On the other hand, NATO's intervention in Kosovo, even though being missioned for the protection of human values, additionally aimed for its geopolitical and hegemonic strategies in the world of anarchic international political system. Yet, in the theory of international relations, this might be classified as a structure of offensive realism. The main purpose of this article is to investigate the position of realism claiming that; the exclusive monopoly in the use of power belongs to states. In addition, this study aims to unfold the criticisms that realism uses against any foreign interference in domestic affairs. Yet, states are major actors in the anarchic global system that possesses a sole monopoly towards their people and sovereignty. Any kind of domestic disturbances and intervention from abroad is strongly condemned and violates the principle of non-interference in the internal affairs of other sovereign states.