The discipline of International Relations (IR) has largely been built upon theoretical frameworks derived from European historical experiences since the early twentieth century. The dominance of realist theory during the Cold War reinforced the notion that certain power-based assumptions about the nature of inter-state relations are universally applicable. Within this context, power transition theory has emerged as an analytical model frequently employed in IR literature to explain the structural dynamics between established hegemonic powers and rising states seeking greater influence within the international system. However, the foundations and empirical validity of this theory have primarily been tested through European cases, while regions such as Asia, Africa, and Latin America have been largely overlooked. Beyond Power Transitions: The Lessons of East Asian History and the Future of U.S.–China Relations by Xinru Ma and David C. Kang is an original work that challenges this theoretical narrowness and develops a distinct perspective by placing East Asian history at its centre.

The book is grounded in two central arguments. The first posits that regime changes in East Asian history were largely the result of internal decline rather than external aggression. This constitutes a significant critique of the external conflict-based assumptions of power transition theory. The second argument is that the historical East Asian international order was shaped not primarily by balance of power or structural rivalry, but by common conjectures developed among regional actors. In this context, the dynamic of competition and conflict that power transition theory associates with rising material and military power does not hold in the case of East Asia. At this point, the authors introduce the concept of common conjecture, which they present as the study’s most original contribution. The common conjecture denotes the mutual recognition and acceptance by actors in the international system of each other’s roles, forms of legitimacy, status, and behavioral patterns. In other words, the common conjecture encompasses a shared understanding of expected behaviors among actors, and consistent patterns of behavior based on cultural norms that sustain the order between states.

When the common conjecture disappears, the likelihood of conflict and chaos in the regional order increases. According to Ma and Kang, during significant periods in East Asian history, such common conjectures were disrupted or ceased to exist, which led to instabilities within the system. The authors support their core claim with four significant historical case studies: (i) During the thirteenth century, the downfall of the Song Dynasty was determined more by internal decay, fragmentation, and crises of legitimacy than by the military capacity of the Mongols. This case illustrates that internal factors rather than the dominance of a stronger actor played a decisive role in the system. (ii) Even though Japan’s invasion of Korea during the Imjin War (1592–1598) appears to be a revisionist move from an external perspective, it is argued that Japan was not perceived as an equal power with China within the regional system, and that the conflict primarily resulted from the weakening of shared understandings and common conjectures. (iii) Although the Qing conquest of China during the Ming–Qing transition appears as an external invasion, the process was made possible by the internal collapse and political fragmentation of the Ming dynasty. The Manchus rose in the system not through material power but by seizing strategic opportunities created by the resulting power vacuum. (iv) Despite the dynastic changes in China, Korea kept its place in the regional order for centuries. This was possible because of clear roles and shared norms, not material power. These examples show that the authors’ approach is supported not only theoretically but also empirically. The authors argue that these historical examples challenge the universality of power transition theory.

Given the historical analysis, the authors make two observations in the context of contemporary US–China relations. The first is that as seen in the decisive role of internal factors in the rise or fall of political entities throughout history, the future of the US and China will be shaped more by internal challenges than external threats. The second is that despite China’s rapid progress in its integration with East Asia, the US has lagged in its economic and diplomatic engagement with the region. The authors emphasize that whether the reflections of these two trends in East Asia will be peaceful depends on the political choices of the parties involved. In other words, whether the US and China can develop a shared common understanding will serve as a critical determinant of the nature and direction of both East Asian and international security.

Ma and Kang’s conceptualization of common conjecture, along with their examples, directly challenges the approaches of classical power transition theorists such as A. F. K. Organski, Jacek Kugler, and Robert Gilpin. According to these theorists, as the current hegemon weakens within the international system, a rising power attempts to take its place—a struggle that often leads to war. The authors, by contrast, argue that the historical experience of East Asia does not conform to this model, as the stability of the regional order was grounded not in power, but in a shared understanding among regional actors. The book also stands in clear opposition to Graham Allison’s “Thucydides Trap” thesis. While Allison argues that China’s rise makes conflict structurally inevitable, Ma and Kang suggest that conflict may stem not from structural factors but from the breakdown of shared understanding and common conjecture. The authors also question the structural realist assumption that states act based solely on material interests, and instead highlight the role of identity, history, and culture in shaping state behavior.

The study situates itself in the literature not only through its focus on power, but also by questioning how knowledge is produced in the discipline of IR. In this sense, the book advocates epistemological pluralism, arguing that theory production should not be based solely on Western history but can also be derived from different historical traditions, such as those of East Asia. With this approach, the book establishes a direct connection with the recently developed “Global IR” project, primarily advanced by Amitav Acharya and Barry Buzan, along with several other scholars. By drawing on regional experience to question existing approaches and propose a new one, the book presents a strong challenge to the Western-centered nature of the IR discipline.

The book breaks new ground in several key areas, foremost among them being theoretical innovation. By offering a historically and culturally grounded explanation as an alternative to structural and conflict-based theories such as power transition, it provides a new basis for theory development in the discipline of IR. Epistemologically, it positions East Asian history not merely as a testing ground, but as a source of theoretical knowledge production. The book also offers conceptual depth. Through a new concept such as common conjecture, it seeks to explain the conditions under which stability in the international system is maintained or disrupted. Finally, in terms of policy relevance, the book explores how a contemporary issue like China’s rise may influence the international system and US–China relations through historical examples, thereby offering fresh insights into current dynamics.

On the other hand, the most significant weakness of the book is its failure to operationalize the concept of common conjecture. While the concept is theoretically strong, the book does not clarify how it can be measured or which indicators can be used to analyze it. This lack of clarity limits the concept’s academic applicability. Moreover, the book does not sufficiently analyze whether China’s recent foreign policy agenda, including the South China Sea, the Taiwan issue, and the Belt and Road Initiative, generates a shared understanding and common conjecture. This limits the book’s ability to contribute to the understanding and explanation of current developments.

To conclude, the book is not only a historical critique of the power transition theory, but also a bold intervention into the epistemological structure of the discipline of IR. Ma and Kang’s study shows that norms, historical meanings, and perceptions regarding cultural roles can be key determinants in the functioning of the international system. In this respect, the book highlights shared understandings rather than conflict, emphasizes legitimacy over hegemony, and focuses on actors’ perceptions of one another instead of power transitions. The central message of the book is clear: the discipline of IR should not only ask “who is more powerful?” but also “who is considered legitimate, when, how, and why?” as well as “what is the significance of internal dynamics?” Posing these questions through the lens of East Asian history and analyzing contemporary US–China relations within this framework can broaden the scope of the discipline and offer a non-Western epistemological perspective. The book represents one of the significant steps taken recently towards shaping the future of the discipline in this direction.