Dialectic of peace and barbarism: Studying and criticizing the liberal theory of international law

International law reviews the origins of the rules, institutions and practices that international law based on. That’s why "Theory" in law is able to give legitimacy to certain procedures and rule. From this standpoint, the "Liberal Theory of International Law" has an important place in international law. Confirmed by various studies, this theory plays an important role in forming "Peaceful" approach to international law and set aside classical approaches that recognized nothing butt "Legitimacy of War". Nevertheless, the core elements of this theory, reveals the fact that not only the liberal theory of international law helps to achieve the peaceful approach in international law, but also helps to justify use of force. This article studies the dualities and contradictions in the context of liberal theory of international law.