Realism, in its various forms, has been a leading approach to the research of international politics and great power relations during the era of the Cold War.
Thereafter other approaches like liberalism and constructivism have challenged its position and nowadays those three are the main trends in the research of international politics.
Realism concentrates on power competition of sovereign states, especially great powers and their security problems as well as on international order (world order) and systemic stability, in other words on the problem of peace and war. Therefore realism is the most competent reseach approach to great power relations.
There are different doctrines or schools of realism but classical realism and neorealism or structural realism can be defined, sometimes even neoclassical faction is mentioned. Some 30 years ago, classical realism was mostly replaced by neorealism.
Western dominance has been striking in the formation of international relations theory (IRT). This is because the origin of most major IRT is in the Western philosophy, political theory and history. Another reason is the Eurocentric framing of world history, which manifests itself through and around much of this theory.
Not until in late Cold War and thereafter, in Russia the academic research began to take seriously this discipline and in China this interest emerged along the general opening of Chinese society in 1990s and early 2000s.
So far, the actual formation of IRT has been a Western “privilege” but especially Russian researchers have been active in applying Western doctrines (e.g. realism) in the foreign policy research and in strategic studies in recent years.
Sino-Russian arising discourse in multipolarity became really public in April 1997, when Russia and China signed the “Joint Declaration on a Multipolar World and the Establishment of a New International Order” and in May the declaration was registered in the UN.