Hegemonic stability theory (HST) is a theory of international relations, rooted in research from the fields of political science, economics, and history. HST indicates that the international system is more likely to remain stable when a single state is the dominant world power, or hegemon. Thus, the end of hegemony diminishes the stability of the international system. As evidence for the stability of hegemony, proponents of HST frequently point to the Pax Britannica and Pax Americana, as well as the instability prior to World War I (when British hegemony was in decline) and the instability of the interwar period (when the American hegemon retrenched itself from world politics).
The key mechanisms in hegemonic stability theory revolve around public goods provision: to resolve collective action problems regarding public goods, a powerful actor who is willing and able to shoulder a disproportionate share of public goods provision is needed. Hegemonic stability may entail self-reinforcing cooperation, as it is in the interest of the hegemon to provide public goods and it is in interest of other states to maintain an international order from which they derive public goods.
Charles P. Kindleberger is one of the scholars most closely associated with HST, and is regarded by some as the theory's most influential proponent. In the 1973 book The World in Depression: 1929-1939, he argued that the economic chaos between World War I and World War II that led to the Great Depression was partly attributable to the lack of a world leader with a dominant economy. Kindleberger's reasoning touched upon more than economics, however: the central idea behind HST is that the stability of the global system, in terms of politics, international law, and so on, relies on the hegemon to develop and enforce the rules of the system. Other key figures in the development of hegemonic stability theory include Robert Gilpin, and Stephen Krasner.
Robert Keohane coined the term "Hegemonic stability theory" in a 1980 article. Keohane's 1984 book After Hegemony used insights from the new institutional economics to argue that the international system could remain stable in the absence of a hegemon, thus rebutting hegemonic stability theory. John Ruggie's work on embedded liberalism also challenges hegemonic stability theory. He argues that the post-WWII international order was not just held together by material power but through "legitimate social purpose" whereby governments created support for the international order through social policies that alleviated the adverse effects of globalization. John Ikenberry argues that hegemony is not a precondition for international stability, pointing to path dependence and "stickinesss" of institutions.
In order for a nation-state to rise to the level of hegemon, there are some attributes it must or is more advantageous to have.
First of all, it must have political strength, military force, and superior national power that is necessary for its ability to forge new international laws and organizations. In terms of military force, a standing defensive army is not enough. A superior navy, or air force is. This explains why many hegemons have been geographically situated on peninsulas or islands. Peninsularity and insularity provide added security, and, where naval power is necessary, the ability to project military forces. In some cases, hegemons have not been insular or peninsular. The United States of America, for instance, has become a virtual island. It has two massive seaboards, and its neighbors are strong allies, and relatively reliable. Also, the modern invention of nuclear weapons, and the presence of a superior air force provide highly reliable security for the country, setting it apart from the rest of the world.
Secondly, a hegemon must have a large and growing economy. Usually, unrivaled supremacy in at least one leading economic or technological sector is necessary.
The first and second refers to a state having the attribute of the capability to enforce the rules of the system.
Thirdly, a hegemon must have will to lead, and the will to establish a hegemonic regime, as well as the capability to lead and enforce the rules of the system. After World War I, Great Britain possessed the will to lead, but lacked the necessary abilities to do so. Without the ability to force stability on the international system, Great Britain was able to do little to prevent the onset of the Great Depression or World War II.
Finally, a hegemon must commit to the system, which needs to be perceived as mutually beneficial for other great powers and important state-actors.
Research on hegemony can be divided into two schools of thought: the realist school and the systemic school. Each school can be further sub-divided. Two dominant theories have emerged from each school. What Robert Keohane first called the "theory of hegemonic stability," joins A. F. K. Organski's Power Transition Theory as the two dominant approaches to the realist school of thought. Long Cycle Theory, espoused by George Modelski, and World Systems Theory, espoused by Immanuel Wallerstein, have emerged as the two dominant approaches to the systemic school of thought.
According to Thomas J. McCormick, scholars and other experts on the systemic school define hegemony "as a single power's possession of 'simultaneous superior economic efficiency in production, trade and finance.'" Furthermore, a hegemon's superior position is considered the logical consequence of superior geography, technological innovation, ideology, superior resources, and other factors.
George Modelski, who presented his ideas in the book, Long Cycles in World Politics (1987), is the chief architect of long cycle theory. In a nutshell, long cycle theory describes the connection between war cycles, economic supremacy, and the political aspects of world leadership.
Long cycles, or long waves, offer interesting perspectives on global politics by permitting "the careful exploration of the ways in which world wars have recurred, and lead states such as Britain and the United States have succeeded each other in an orderly manner." Not to be confused with Simon Kuznets' idea of long-cycles, or long-swings, long cycles of global politics are patterns of past world politics.
The long cycle, according to Dr. Dan Cox, is a period of time lasting approximately 70 to 100 years. At the end of that period, "the title of most powerful nation in the world switches hands.". Modelski divides the long cycle into four phases. When periods of global war, which could last as much as one-fourth of the total long cycle, are factored in, the cycle can last from 87 to 122 years.
Many traditional theories of international relations, including the other approaches to hegemony, believe that the baseline nature of the international system is anarchy. Modelski's long cycle theory, however, states that war and other destabilizing events are a natural product of the long cycle and larger global system cycle. They are part of the living processes of the global polity and social order. Wars are "systemic decisions" that "punctuate the movement of the system at regular intervals." Because "world politics is not a random process of hit or miss, win or lose, depending on the luck of the draw or the brute strength of the contestants," anarchy simply doesn't play a role. After all, long cycles have provided, for the last five centuries, a means for the successive selection and operation of numerous world leaders.
Modeslki used to believe that long cycles were a product of the modern period. He suggests that the five long cycles, which have taken place since about 1500, are each a part of a larger global system cycle, or the modern world system.
Under the terms of long cycle theory, five hegemonic long cycles have taken place, each strongly correlating to economic Kondratieff Waves (or K-Waves). The first hegemon would have been Portugal during the 16th century, then the Netherlands during the 17th century. Next, Great Britain served twice, first during the 18th century, then during the 19th century. The United States has been serving as hegemon since the end of World War II.
The traditional view of long cycle theory has evolved somewhat, as Modelski now suggests that Northern and Southern Sung China, Venice and Genoa were each the dominant economic powers during medieval long cycles. However, he does not classify any of these states as world powers. Only when Portugal gained hegemony after 1500 is that distinction made.
Neorealists have been focusing on this theory recently, the main proponent of it being John J. Mearsheimer who is trying to incorporate it into 'offensive realism'. In his book 'The Tragedy of Great Power Politics' Mearsheimer outlines how the anarchic system that neorealists subscribe to (see Kenneth Waltz for original theory) creates power hungry states who will each attempt to install themselves as regional and global hegemons. The system is created, shaped and maintained by coercion. The hegemon would begin to undermine the institution when it is not in their interests. With the decline of a hegemon, the system descends into instability.
Neoliberals argue that the hegemon wishes to maintain its dominant position without paying enforcement costs, so it creates a system in which it can credibly limit the returns to power (loser doesn't lose all) and credibly commit to neither dominate nor abandon them. This is done through institutions, which are sticky, (hard to change, more convenient to continue using than to revamp.) These institutions favor the hegemon, but provide protection and a stable world order for the rest of the world. The more open this world-order, the less likely that there will be a challenger. With the decline of the hegemon, institutions don't automatically die, because they were constructed in a way that benefited all stakeholders; instead, they take on a life of their own (see regime theory).
It is motivated by 'enlightened self-interest'; the hegemon takes on the costs because it is good for all actors, thereby creating stability in the system, which is also in the interests of all actors.
Keohane's 1984 book After Hegemony used insights from the new institutional economics to argue that the international system could remain stable in the absence of a hegemon, thus rebutting hegemonic stability theory. Keohane showed that international cooperation could be sustained through repeated interactions, transparency, and monitoring. These factors could reduce transaction costs and provide information about other states (for example, whether the states are cheating or contributing). Duncan Snidal argues that international cooperation is sustainable even after hegemony because smaller states derive sufficient benefits to be willing to contribute towards international institutions.
Using insights from historical institutionalism, John Ikenberry argues that the international institutions set up by the United States are sustainable due to feedback effects, whereby it is costly for actors to set up alternative institutions. Ikenberry also argues that hegemonic stability theory fails to account for regime types, which is essential to understanding why democratic hegemons such as the United States created institutions during periods in which they were hegemons, whereas non-democratic hegemons in previous eras did not set up institutional orders when given the opportunity. Consistent with hegemonic stability theory, Ikenberry argues that the ability to create institutions is partly due to power preponderance.
Dominic Tierney argues that hegemonic stability theorists are wrong in assuming that unipolarity leads to a stable order. He argues that it is the contestation that compels the great power and other states to build international order.
Maria Gavris has criticized HST for its underdeveloped conceptualization of hegemony.
Hegemony demands power, which is defined by the British scholar Susan Strange as the ability of one party to affect outcomes such that their preferences take precedence over the preferences of other parties. The question of whether the United States is still a hegemon is tied into whether or not it has lost power. Keohane sees power as tied into resources and production. The US GDP is now lower relative to others as there are growing economies with considerable amount of GDP such as BRIC countries. This implies a loss or decreased power of US as a hegemon.
Although resources are an important determinant of power, they are not always determinative. For example, the German troops that conquered western Europe were actually fewer in number than their opponents. Susan Strange uses this logic to argue that the United States is still a hegemon.
The United States unilaterally helped Mexico in the Peso Crisis and unilaterally helped Russia with economic aid. The United States has also been influential in moving many countries towards embracing the free market; through institutions such as the International Monetary Fund, the United States has pushed Latin American nations to undertake economic programs in accordance with its own foreign policy Interests (see Washington Consensus).
The United States is still considered by most analysts to be at the top of the world, both economically and in terms of military strength. With these abundant resources and power in the hands of the United States, they still remain as the leader "in a single superpower world". However, the emergence of new giants threatens U.S. hegemony by creating new power centers all over the world. Of those new giants, the single greatest competitor of United States is China as they are growing rapidly with "no equal in modern history".
Historically, examples of hegemonic decline come in two prime sectors: the leading state's military and its economy. Thus, it is important to look at China's emergence in both arenas and more to understand the shifting power structure.
With the second highest gross domestic product at purchasing power parity, China poses a significant challenge to U.S. economic primacy especially with the expectation that U.S. national debt could explode to 717% of GDP by 2080 according to Congressional Budget office. Moreover, this debt is financed largely by China through the purchase of U.S. Treasury bonds. On the other hand, China's economic power, not limited to but including industrialization and modernization, is rapidly burgeoning with high consumption and increasing foreign investment. As Global Trends 2025 points out, the rise of China and India to great power status will restore each to "the positions they held two centuries ago when China produced approximately 30 percent and India 15 percent of the world's wealth" (p. 7).
U.S. military can be characterized by "imperial overstretch" with troops operating abroad in more than fifty-five countries. Through this process, "a military force is extended so much that it nears a breaking point." On the other hand, China is taking advantage by industrializing its army using their wealth. China's military budget is increasing and the troops are expanding. Steven W. Mosher insists that China is building up its armed forces "to break America's back in Asia and thus end America's reign as the sole superpower in the world."
However, many argue that China has a symbiotic relationship with the United States. If the United States declines, it is likely that China also may be in jeopardy. John Gulick points out that China's prosperity is "deeply ensconced in the 'China produces and lends, the US borrows and spends' framework". Economic interdependence of China derives from the fact that they are a producing state rather than a consuming state. China's economy is export heavy as its driving force lies in "export processing measures". The export dependent structure could severely dampen economic growth if demand for Chinese exports is reduced by another economic crisis in the United States. Thus, China's economic woes are one of the barriers to its hegemonic aspirations. However, it is not the only barrier that China must overcome to achieve from hegemony. In fact, HST demonstrates that their needs theoretical requirements for world leadership that China should strive to achieve in order to gain hegemonic status that include whether China has the will to lead and the ability to lead. Also, other factors- for example, domestic political instability, environmental degradation, public health issues, and demographic trends- could possibly hinder China's ascent to great power status.
Gilpin's argument opposes balancing and the balance of power theory. His theory targets the system by analysis. He contends that the system naturally goes toward equilibrium. To acquire a new system, global war or "hegemonic war", definitionally creates a new hegemon. This new hegemon will create the new system of the world with their own set of preferences. Similar to a global war, the hegemon's job is to keep their newly founded order. They accomplish this by providing public goods; examples include the United States attempts at initialising a stable currency by means of the International Monetary Fund, the Bretton Woods system, establishment of the World Bank, world defence (NATO), and democratisation. These are norms that the U.S. have shown preference towards and have spent the past several decades demonstrating their new system.
Gilpin argues further that by the global system, the more decisive a victory is after the "hegemonic war", the more stable the new system will be. He agrees with Paul Kennedy's claim of "imperialistic overstretch" being one of the reasons that hegemons fall. Gilpin adds that all hegemons inevitably fall because it is difficult to stay as hegemon. To exemplify this concept, if one were to walk into a weight room with robust men at their prime on one side of the room facing men who are working to reach the equivalent of the robust men, they will see that the working men grow muscle much faster than the already robust men. This is because they have more room to grow. It is harder for hegemons to "grow" when they have already grown and expanded so much.
To ensure their preferences, the U.S. as the newest and current hegemon has created institutions for the system to represent their power structure.
Eventually, Gilpin contends, a dissatisfied great power that approaches the power distribution, approaches the equivalence of the current hegemon will cause a new global war and the cycle repeats. Generally, the rising challenger does not go on to become the new hegemon as most of their resources have been depleted fighting the hegemon and do not have more to spare to instil their preferences. Instead, some theorists think, a state similar in culture and preferences to the old hegemon will assume new hegemon status.