A Comparison Analysis of the Realism Theory Development among United States, Japan and China

: Realism has always been the most powerful school of international relations theory. In addition to its long historical origin, realism theory continued to deepen vertically and horizontally with the development of the times. In the United States, realism has developed vertically, mainly explaining the three different stages on the issue of hegemony. In the first stage, classical realism preliminarily explored the pursuit of hegemony; In the second stage, structural realism rationally explained the maintenance of hegemony; In the third stage, offensive realism analyzed and demonstrated the expansion of hegemony. The horizontal development can be mainly shown in that realism theory has its theoretical achievements in both Japan and China. Japanese realism mainly explained foreign policy, and Chinese moral realism explained the problem of power transfer. The strong vitality of realism theory can be reflected in its development both vertically and horizontally.


Introduction
Realism can be said to take the first place in international relations theory. Although the current international relations theory presents a situation of tripartite confrontation, realism theory undoubtedly is still the theoretical paradigm with the most believers and the most extensive influence. Realism international theory is a group of theories with common value orientation and basic assumptions, rather than a single meta-theory. Although different school of realism theories are different, they still have some characteristics in common. Western realism did not rise from the fantasy, but has a long historical tradition. Realism theory can be traced back to the ancient Greek period more than 2,500 years ago, and then continued through the Middle Ages and the Enlightenment. This historical tradition was initiated by the ancient Greek historian Thucydides more than 2,500 years ago, and was jointly established by the Italian thinker Machiavelli in the 16th century, and the British philosopher Hobbes in the 17th century, and the French Enlightenment thinker Rousseau in the 18th century.
But in the real scientific significance, the realism theory was formed in the United States after World War II. Realism theory has experienced three stages of evolution in United States: Classical Realism, Structural Realism and Offensive Realism. Outside the United States, realism has also taken root, among which Japanese Realism and Chinese Moral Realism are relatively more typical. This paper aims to summarize the reasons why the same theoretical origin forms different development paths by comparing the realism development among the three countries. The development of American realism mainly serves to explain American hegemony, thus it is macroscopic and universal; Japanese realism is microscopic and flexible for it mainly proposed to solve Japanese diplomatic problems. Chinese moral realism attempts to explain the problem of power transition with both macroscopic universality and microscopic flexibility.

Classical Realism
Although realism has a long history and theoretical origin, the scholar who really established the realism theory building is Hans Morgenthau. [1] Morgenthau was known as the Pope of International Relations for his book Politics among Nations: Power Struggle and Peace published in 1948. After World War II, the traditional capitalist powers generally weakened. Gone are the days when European powers dominated world politics. The United States became the most powerful country and the American ruling clique publicly proposed to lead the world. Under the background of Cold War at that time, realism, with its theoretical realism, provided a decision-making framework for the foreign policy of the United States to seek the hegemony. [2] Stanley Hoffman argued that realism was nothing but a rationalized expression of Cold War policy. Although this statement was a bit extreme, it did capture the essential problem. After the Second World War, the two superpowers, the United States and the Soviet Union, formed two groups with opposing interests, and they competed and confronted each other fiercely. [3] As a result, people started to study methods to achieve national interests and stabilize the world situation by applying realism theory as an analytical tool. This objectively improved the status of realism theory, and also promoted the development of realism theory itself, making it gradually form a complete theoretical system.
Morgenthau summed up his theory of international relations as the Six Principles of Realism. [4] First, politics was governed by objective laws rooted in human nature. Classical realism was based on a pessimistic view of human nature, believing that the biggest characteristic of human nature is selfishness and greed. Therefore, pursuing power and interests would be continued and extended from people to countries. The country would also take the pursuit of power as the first priority. Second, the key to understanding international politics was the concept of national interests defined by power. After World War II, the United States has the greatest power as the most powerful country in the world. Therefore, the United States must pursue the maximization of interests-that is, American world hegemony. [5] Third, interests defined in terms of power were generally applicable objective principles. Fourth, universal morality was not able to be used to guide the state behavior. Universal moral principles were meaningless unless they were combined with specific state actions. Fifth, national morality was not the same as universal morality. Sixth, political realism was an independent theoretical school.
In a word, classical realism guided by the Six Principles of Realism of Morgenthau profoundly explained the international status quo after World War II, and fully expressed the needs of the United States to pursue world hegemony. This was the first stage in the development of realism theory in the United States.

Structural Realism
Since the late 1950s, there had been a de-escalation of the Cold War, especially at the Camp David talks in 1959, which culminated in the first de-escalation between the United States and the Soviet Union. [6] This de-escalation brought the view of struggle for power proposed by classical realism under attack. The confrontation between the United States and the Soviet Union did not lead to conflict but to easing, and the bipolar pattern did not collapse but stabilized. Realism urgently needed a new theory to explain the various phenomena emerging in international relations.
For the two superpowers, the United States and the Soviet Union, maintaining the stability of the bipolar pattern and the peace of the international environment would be the best choice for them to serve the interests of their own countries. Morgenthau's classical realism explained the problem of conflict and confrontation well, but it was difficult to explain the problem of peace and stability. As a result, realist theory should be developed internally. The neorealism represented by Kenneth Waltz finally deduced the superiority of the stability of the bipolar pattern through the introduction of structural concepts and the analytic hierarchy process. [7] The representative work was International Political Theory published in 1979.
Waltz made three major revisions to the classical realism represented by Morgenthau. First, the first impetus of international relations is the anarchy of the international system rather than the human nature. Second, the first consideration of a nation under anarchy is survival. The country would be ultimately concerned with security rather than power. Third, Waltz objected to the view of classical realism on causality as one-way, which refer to looking for causes from individuals or nations. However, it was necessary to look for causes both at the unit level and at the structural level, with particular attention to the latter one. [8] After Waltz revised Morgenthau's theory, he put forward his own theory of neorealism, and made three assumptions for this: First, the international system is a system with anarchy as its basic nature; Second, the nation is the basic behavioral unit in this system; Third, the most important factor affecting the stability of the system and the behavior of the systemic unit is the system structure. Based on the three assumptions, it was only necessary to clarify two questionswhat is the international architecture? What role does it play? Under the international system, countries were arranged according to the principle of equality and with similar functions of each. They were all constants, and the only variable was the power difference between countries. Thus, Walz defined international structure as the Distribution of Power among Nations. The international structure determined the behavior of nations within the international system. Since the international system structure was the distribution of power between countries, it would be firstly proceeded among those dominate countries, and power refer to the military strength of a country as the priority. After all, international politics was still a game between the great powers. The system structure was based on the number of great powers and represented in the form of poles. During the Cold War, United States and the Soviet Union as the global powers had important influence on the entire international system, and the international system at that time was the distribution of power between them. In order to maintain its existing hegemony, the United States should maintain the environment of world peace, and the smooth operation of the bipolar pattern to achieved it.
In short, structural realism perfectly explained the need for the United States to maintain the stability of the bipolar pattern and maintain the peace of the international environment. This also explained the various behaviors of the United States in maintaining hegemony at this stage. This was the second stage in the development of realist theory in the United States.

Offensive Realism
With the end of the Cold War, the United States became the only superpower in the world, forming a One Nation Dominated strategic pattern of the world. The economic and military power of the United States far exceeded that of any single nation in history. More importantly, the United States not only possessed hard power such as a strong economy and military, but also had an absolute advantage in soft power such as lifestyle and popular culture.
Realism theory had been criticized for failing to predict the end of the Cold War. In particular, structural realism, the theoretical achievement of realism explaining American hegemony in the second stage was a defensive realism, so it would be even more difficult to have a reasonable explanation for the post-Cold War world situation. In addition, after the end of the Cold War, the view on the world pattern in the international relations academic circle was dominated by optimistic liberalism, and the End of History Conclusion of the Japanese-American political scientist Francis Fukuyama once flourished. Constructivism, which explained the end of the Cold War, formed a triad with realism and liberalism. Realism urgently needed a new theoretical form that would be able to explain American hegemony. In this context, Mearsheimer's The Tragedy of Great Power Politics was conceived in 2001. Its offensive realism became the third stage theoretical result of realism explaining American hegemony.
The offensive realism of Mearsheimer was the Maximum of Realism that pursued power, anarchy, and the hegemony pursuit to the extreme. [9] The offensive realism theory of Mearsheimer held that, first, there are always full of competition among the great powers, maximizing the competition for world power with each other, so as to become the only great power in the system. Second, great powers themselves have military power for attacking, providing the necessary capital for them to harm or even destroy each other, which is the basis of the theory of offensive realism. Third, there are no countries in the international system that maintain the status quo, and major powers almost always have revisionist intentions, that is, they always seek opportunities for change centered on their own interests. Fourth, survival is the primary goal of a great power, and the best way for a country to ensure survival is to be the most powerful country in the system. Finally, great powers are rational actors. Great powers can adopt the following strategies such as war, blackmail, trapping and bloodletting in order to successfully hunt for the power.
As the theoretical achievement of the third stage of realism, offensive realism fully explained the need of the United States to pursue world hegemony in the new stage. Mearsheimer's offensive realism had a huge impact on the foreign policy of the neoconservative Bush administration. [10]

Japanese realism explaining foreign policy
Realism theory were spreading outward gradually when it established the core status in the United States. After World War II, Japan was monopolized by the United States and was deeply influenced, thus soon imported and embraced the realism theory. Due to the overlapping effect of historical tradition and practical politics, realism theory in Japan developed into a refine theory that focused on explaining diplomacy with Japanese eclecticism rather than a general theory that focuses on the macro-international system. [11] In terms of historical tradition, Japanese scholars always attached great importance to historical and regional studies, with academic focus on the diplomatic handling of international relations theory as a political means, rather the international system and the world. [12] In terms of practical politics, as a defeated country Japan should make rationalized explanations on the three major diplomatic issues of peace, armament and security, [13] [14] like how to get rid of its status as a defeated country and how to integrate into the post-war international society. Therefore, their demand for theory was that it fully explained its own diplomatic behavior and foreign policy.
The core views of Japanese realism were as followed. First, to construct a new realism in which power and value coexisted. Kosaka Masataka believed that the value of Japanese diplomacy is peace, which is in line with the basic spirit of the Peace Constitution. While emphasizing the role of power politics, he also advocated that Japanese diplomacy should absorb the long-term vision of the national value and build a peaceful international order on the premise of realizing security. Second, it is different from the traditional view of power and power balance. Kosaka Masataka put forward the famous thesis that international politics is a system of power, interests, and values, [15] that is, the power of a nation includes both military and economic power, as well as soft power. It is advocated that on the premise of maintaining the balance of power, all countries maintain their own ideas and interests and create international law through actions to enhance the authority of the United Nations, so the world peace will gradually achieve. [16] [17] Third, Marine State Concept was proposed by reflecting on the Yoshida Route. Kosaka Masataka believed that Marine State is not only a geographical and economic concept, but also a spiritual and political one. He pointed out that the lack of autonomy was the biggest problem in Japanese diplomacy, and Japan should reorient the country. [18] [19] It is advocated that Japan regarded Maritime Countries as its goal with specific plans. That is, maintain a minimum amount of armaments in Japan on security issues and adjust Japan-US relations, meanwhile develop relationships between developing countries and exploite the oceans on development issues. For the development of developing countries, Japan should first formulate an aid policy combining with the trade policy. Second, to assist the developing countries with the consideration of regions and locations. And third, as the core of the aid policy, technical assistance should be paid more attention to. When it comes to the ocean development, first, about one-third of the current self-defense force budget of Japan should be used for ocean surveys. Second, Japanese offshore waters should be surveyed with the Maritime Self-Defense Force as the center. Finally, based on the principle of international cooperation, scientists would be sent to investigate the oceans around the world. [20] In these ways, on the one hand, with Maritime Nations Concept, Japan develops its economy through foreign trade with the advantage of the geographical environment surrounded by the sea. On the other hand, it promotes a more active foreign policy and gradually strengthens its own strength.
In short, Japanese realism was founded to solve diplomatic problems. This theory attempted to bridge the so-called opposition between interests and morality, strength and value. In the context of the Cold War at that time, the Japanese diplomatic strategy planned by Japanese realism was undoubtedly rational and with Japanese characteristics. On the one hand, it adhered to the realist international political concept based on power politics; on the other hand, according to the actual situation of Japanese domestic political practice, it focused more on advocating the auxiliary role of value concept. Japanese realism started from the awareness of domestic problems, and pursued a foreign policy orientation that integrated domestic opinions to the greatest extent and effectively realized national interests. This theory is not influenced by preconceived paradigms, but its views are more explanatory, which is very consistent with Japanese diplomatic philosophy. As a micro-theory to explain foreign policy, Japanese realism was undoubtedly successful.

Chinese Realism Explaining Power Shifts
At present, the most concerned issue in the world is the rise of China. Especially under the background of the relatively weakened US hegemony, how China can rise without war or conflict is a major topic of concern for the domestic scholars. Professor Xuetong Yan of Tsinghua University put forward Chinese proposed law -moral realism. Moral realism belongs to the category of neoclassical realism theory. Based on the assumptions of realism about strength, power and national interests, the significance of morality in the rise of great powers was rediscovered from the individual level. [21] Moral realism is an international relations theory emphasizing that political leadership determines the comparative change in the power balance of major powers, and the variations of the international system. The core question of this theoretical study is how the rising power replaces the dominant power of current world, that is, the principle of shifting the world center.
Moral realism has the following four inferences. First, the pursuit of profit is the fundamental driving force for the evolution of state behavior and international norms. The dominant country pursuing for their own interests are the driving force behind the establishment and the evolution of international norms. Maintaining the international order is the greatest strategic interest for the dominant country, as it ensures that country has the greatest international power. Second, different types of countries in the disordered system have different security self-preservation strategies. The differences in the types of dominant powers determine the differences in international norms. Moral realism divides the dominant powers into three categories, that is, royal power, hegemony, and mighty power. Different major powers will adopt different strategies to gain more power. Third, the zero-sum nature of power leads to structural contradictions and system pressures in the rise of great powers. Fourth, changes in political power are able to change the balance of power. Political leadership determines the rise and fall of comprehensive strength for the country, and differences in political leadership determine changes in the international pattern.
Moral realism has advanced the theory of neoclassical realism in the following three aspects. First, compared with neoclassical realism, moral realism pulls the research perspective from the micro-orientation of analyzing foreign policy to macro-orientation of explaining power transfer problem in international structure, which prevents the denial of the universality from realism theory. Moral realism is not studied from the perspective of how to maintain hegemony, but from the perspective of how to replace hegemony. It opens up a new development direction, that is, from the perspective of political leadership type to explain and analyze the foreign strategic orientation of the leading countries in the world, the transformation mechanism of the international pattern, the evolutionary trend of international norms, the international order stability, and the transition of the international system. [22] Second, compared with neoclassical realism, moral realism has fewer variables and is easy to operate, which avoids the broke down of the theoretical simplicity in realism. [23] Moral realism believes that power is the most important part of national interests and the goal achieved by national foreign policy while strength is the basis for defining national interests and a tool for realizing national interests. From this, we can draw the conclusion that power is the interest, and strength defines interest. Morality can not only enhance the legitimacy of power, but also strengthen its own strength, thereby increasing strategic credibility, establishing international authority, and ultimately realizing the transferring of international dominance.
Third, compared to neoclassical realism, the core logic of the moral realism theory is very simple, that is, the foreign strategic choice for a country is determined by its objective national interests, the interest precedence and its realization methods. [24] National interests and perceptions are determined by the comprehensive strength and leadership type of the country respectively. The moral realism theory attributes the phenomenon of the weak over the strong to the fact that the political leadership of the weak is better than that of the strong, and the strength of political leadership mainly depends on the type of political leadership.
According to the theory of moral realism, countries are divided into four following categories: dominant countries, rising countries, regional powers, and small countries. Taking China, the United States, and Japan as examples, the following table compares their strategic choices.
Moral realism attempts to explain why the rising power is able to win the competition under the condition of being weaker than the dominant power and replace the dominant power in the international position. As an enterprising rising country, Chinese moral realism explains the logic of Chinese foreign policy well, with certain universality as well. The practice of the current concept of major-country diplomacy with Chinese characteristics of Responsibility for the Country and Duty for the World acquires the theoretical guidance of moral realism, and seeks an international recognition mechanism with morality. The rise of China is inseparable from morality, and China should pay attention to the advantages of morality in the national diplomatic strategy to enhance its international identity. In table 1, different strategies are applied in the development of moral realism.  From table 2 it can be seen that realism theory of international relations, with its strong vitality and innovation ability, has always been the navigator of the national relations theory. In the United States, realism as a macro theory has always emphasized its universality, but the pursuit of this universal value precisely reflects the particularity of the United States, especially around the issue of hegemony. Realism has experienced the innovation and development of the three stages --classical realism, structural realism and structural realism which corresponds to the deep logical evolution of pursuing hegemony, maintaining hegemony, and expanding hegemony. In Japan, realism developed into a micro-theory to explain Japanese foreign policy. Japanese realism has the characteristics of Japanese eclecticism. As a country-specific theory, its views are more explanatory and more in line with Japanese diplomatic concepts and traditions. At the beginning of its establishment, moral realism was different from Organsky and Robert Gilpin's theory of hegemony transfer. It did not study from the perspective of how to maintain hegemony, but from the perspective of how to replace hegemony. It not only provided the strategic choice but also the value concept for the rise of China. In conclusion, the cognition of realism theory was deepened by the comparison of different categories. It is hoped that there will be more realism factions in the future to further deepen the theoretical connotation vertically, and more realism types with regional and country characteristics appeared to enrich the theoretical development horizontally.