This article is devoted to the study of world order in modern political theory. The author shows that modern Anglo-American and Russian political science share common problems related to its study. First, modern internationalists often unjustifiably take the modern world order out of the context of historical development, contrasting it with the entire world history. Second, modern theories of world order are characterized by a high degree of normativity: political processes are assessed from moral and ethical or openly ideological (usually liberal) positions. Third, researchers today often exaggerate the originality, or uniqueness, of the modern world order, although many of its problems existed in the past. Also, in modern political literature the concepts of "order" and "system" are often confused. Moreover, the mechanism of change of world orders, their qualitative difference from each other, even their number and names have not been revealed. In this regard, the author focuses on two interrelated tasks: 1) to define the relationship between the terms "system" and "order of international relations"; 2) to designate the systemic characteristics of world orders, which will make it possible to identify their number, the mechanism of their change and their qualitative difference. The article aims at clarifying the terminology on the subject of world orders and suggests considering them as completed political systems, which have covered their development cycle – from inception to disintegration. The basic concept of the order is that of balance of power between the great powers and the values and rules of interaction established on its basis. The world order emerges as the result of a total war and is terminated by a total war. Some limited wars regulate relations within the world order. The two types of world orders, namely, the hegemonic order and the balance of power order, acted as two equal types of order. Their disintegration is due to objective reasons, namely, the change in the balance of power and degradation of legal norms, which leads to the emergence of extra-systemic revisionists. The author believes that today’s Yalta-Potsdam order is likely to follow the entire cycle of the development of its predecessors.