In Unit 6, we will explore international politics. Before you begin, refer back to the very first article in the course and re-read the section on international relations. International relations is the study of relationships between countries and international organizations. Most international relations courses will begin with a discussion of the Peace of Westphalia, which is regarded by some scholars as marking the beginning of the international system we have today. The "Westphalian System" refers to the fact that the international system is composed of sovereign nation-states. As you will discover, state sovereignty is a key feature of the international system.