Theories of International Relations

Although the formal elaboration and study of international relations (IR) began only in the 20th century, people have been thinking systematically about world politics for far lon ger.  The unsentimental power politics emphasis of Realism in the present era has its antecedents in the writings of Thucydides and Sun Tzu, as well as later thinkers such as Niccolo Machiavelli of the 16th century.  Likewise, the idealistic view of human nature and the possibility of human progress propounded by Liberalism is rooted in the writings of such Enlightenment philosophers as Immanuel Kant, John Locke and Jean-Jacques Rousseau — as well as Thomas Jefferson and other founders of American democracy.

The Liberal perspective was dominant in many intellectual circles in the aftermath of World War I (which in that optimistic interlude was called “the War to End All Wars”), when President Woodrow Wilson and other idealists promoted the League of Nations, treaties abolishing war and the like.  However, the obvious failure of such efforts to prevent the Second World War helped bring Realism into the prominence it held throughout the Cold War.
Deeper theoretical explorations and the emergence of new empirical challenges, particularly after the end of the Cold War, have brought changes in IR theory.  Among the new factors are: multi state political formations (e.g., the European Community), the growing influence of nongovernmental domestic forces in foreign policy decision making, the sudden prominence of non-state international terrorism, the globalization of commerce and communications, the potential of private individuals to influence international behavior (e.g, the Land Mines Treaty) and demands by previously ignored voices of women and minorities seeking to gain a hearing for their perspectives on international behavior. The summary comments below present only a brief (and inevitably simplistic) sampling of a rich and growing intellectual field.  Suggested readings at the end of each segment guide the interested student toward major contemporary works dealing with specific theories.


Realism is characterized by a concern with material coercive power.  It treats states as the primary unit of analysis.  Power is primarily viewed in military terms, and the military power of other states presents the greatest potential danger to an individual state.  Economic leverage is also considered an important element of national strength, and Realist analyses of international economics assume that hegemonic actors define not just political but economic structuresRealists have also long rejected notions such as that free trade or scientific progress might lead to long-term peace, viewing such ideas as dangerous chimera.  Realism is characterized by a belief that international politics are “tragic” in the sense that normative and ethical concerns cannot change a system of incessant competition and threat of open hostilities.  Neorealism, a structuralist variant of Realism, focuses on ways that the global distribution of power relationships shapes the actions of states.

  • Carr, Edward Hallett. The Twenty Years' Crisis, 1919-1939: An Introduction to the Study of International Relations. Edited by M. Cox. Hampshire; NY: Palgrave, 2001 [1945]
  • Mearsheimer, John J. The Tragedy of Great Power Politics. 1st ed. New York: Norton, 2001.
  • Morgenthau, Hans Joachim. Scientific Man Vs. Power Politics. Chicago, Ill.,: The University of Chicago Press, 1946.
  • Thucydides. History of the Peloponnesian War. Translated by R. Warner. New York: Penguin Classics, 1972.
  • Waltz, Kenneth Neal. Man, the State, and War : A Theoretical Analysis. New York: Columbia University Press. 1959.



Liberalism is a perspective on international politics which views the state as the unit of analysis, but also includes international law, international organizations and nongovernmental organizations as increasingly important factors in world politicsLiberal theorists reject the Realist presumption that international relations are a zero-sum game, but instead view them as a system of interactions holding the potential for mutual gain.  Cooperative and peaceful international behaviors are therefore both possible and desirable.  Many Liberals also hold that republican government and democratic capitalism tend toward increasingly harmonious interstate relations, or propound the “democratic peace theory” that liberal democracies are inherently disinclined to make war against each other.  Contemporary Liberal scholars of international relations typically pursue research on economic and political inter dependence and non military sources of power (e.g., economic power and “soft power”), as well as such subjects as minority rights and free trade issues.  Although Liberalism has long argued that economic and political integration produce peace, some scholars have called for offensive military actions against illiberal regimes.  Samuel Huntington sees Liberalism as a uniquely European phenomenon and predicts conflict with other civilizations, while Francis Fukuyama has argued that Liberalism represents the final stage in human political evolution. 

  • Doyle, Michael W. "Liberalism and World Politics." The American Political Science Review 80 (4):1151-1169 (1986).
  • Fukuyama, Francis. "The End of History." The National Interest (Summer), 1989.
  • Kant, Immanuel. Perpetual Peace, and Other Essays on Politics, History, and Morals. Translated by T. Humphrey, Hpc Philosophical Classics Series. Indianapolis, IN: Hackett Pub. Co., 1983[1795].
  • Keohane, Robert O., and Joseph S. Nye. Power and Interdependence. 2nd ed. [Glenview, Ill.]: Harper Collins Publishers, 1990.
  • Moravcsik, Andrew. "Taking Preferences Seriously: A Liberal Theory of International Politics." International Organization 51 (4):513-553 (1997).



Constructivists hold that most phenomena found in world politics –- such as state sovereignty, national identity, legitimacy, ideologies and political institutions -– are the result of social action (i.e., “constructed”) and therefore not immutable.  Through a Constructivist lens ideas (e.g., anarchy, America, Islam, Christianity, freedom), identities (e.g., American, Westerner, evil-doer, foreigner) and norms (e.g., that democracy is the appropriate form of political organization) are central elements of world politics.  This proposition directly contrasts with the Realist or Liberal view that ideas are of little real consequence to the most fundamental measures of influence –- i.e., the distribution of power or the accumulation of wealth.  To the extent that it is meaningful to talk about international actors as having “interests,” these are constructed out of norms, ideas and other cultural resources.  If the rules and norms governing behavior can be “reconstructed,” then new patters of international behavior may ensue.

Constructivism divides into two “moods” or varieties:

Realist Constructivists read social and political realities as not structurally determined, but rather as accomplishments of people (e.g., state officials, soldiers, protesters, academics, experts, reporters) acting together in particular times and places.  They focus on the role of power conceptualized as inhering in social practices, especially the practice of interpretation through which, for example, a bombing becomes defined as an act of terrorism.   The Realist Constructivist investigates how power relations operate within particular situations by analyzing recurrent combinations of practices aimed at achieving specific results.  In doing so, they pay particular attention to the cultures and identities of the actors on the international stage.

Liberal Constructivists place their emphasis less on actions than on ideas and norms that ultimately reside in people’s heads.  While Liberal Constructivists accept that material factors, including the distribution of power, are important, they see the overarching structure of norms as even more important.  Moreover, such ideas and norms cannot be reduced to material power and material constraints do not determine the formation of particular ideas.  Research focuses on cross-cultural communication and such issues as explaining the creation of norms (such as the human rights norm), their dissemination among individuals and political actors, and their effects on the behavior of those actors.

  • Hansen, Lene. Security as Practice, New York: Routledge, 2006.
  • Jackson, Patrick Thaddeus. Civilizing the Enemy, Ann Arbor, MI: Michigan University Press, 2006.
  • Neumann, Iver. Uses of the Other, Minneapolis, MN: University of Minnesota Press, 1999.
  • International Studies Review 6, no. 2: June 2006
  • Finnemore, Martha National Interests in International Society, Ithaca, NY: Cornell University Press, 1996.
  • Keck, Margaret E. and Kathryn Sikkink. Activists Beyond Borders, Ithaca, NY: Cornell University Press, 1998.
  • Katzenstein, Peter J., ed. The Culture of National Security: Norms and Identity in World Politics, New York: Columbia University Press, 1996.


International Political Economy

International Political Economy (IPE), also called Global Political Economy (GPE), looks at how power relations, international economics and politics interact in the world environment.  There are three main strands of IPE: Economic Liberalism, Mercantilism and Marxism.
Economic Liberalism, following in the tradition of Adam Smith and David Ricardo, stresses the value of a capitalist market economy that operates according to its own laws and, when freely allowed to do so, maximizes benefits for individuals, companies and nations.  The World Trade Organization (WTO) embodies the values espoused by this strand of IPE.  Mercantilism holds that the economy should be used to enhance state power, and thus be subordinate to politics.  Protectionist and other policies that minimize dependence on other states are promoted, as are policies of state-led development.  Marxism sees the economy as a crucible of exploitation and inequality between classes, one in which the dominant economic class also dominates politically.  It holds that capitalist development contains contradictions that will eventually produce crisis conditions affecting both social classes and nation states.  Within IPE, ”world system theory” describes the capitalist international economic system as consisting of core, peripheral and semi peripheral areas defined by their modes of labor control and specializations.  In doing so, these theorists promote greater recognition of how underdeveloped countries are exploited by those with capital.

  • Cox, Robert. Production, Power and World Order: Social Forces in the Making of History. New York: Columbia University Press, 1987.
  • Gilpin, Robert. Global Political Economy: Understanding the International Economic Order. New Jersey: Princeton University Press, 2001.
  • Gramsci, Antonio. Selections from the Prison Notebooks, ed. and trans. Quintin Hoare and Geoffrey Nowell-Smith. London: Lawrence and Wishart, 1971.
  • International Political Economy Group of the British International Studies Association Working Papers



Feminism as an approach or theory of international relations comes in many forms, all of which share a concentration on women’s lives and the sources of gender roles -– or “gender politics.”  Feminist theorizing emphasizes that female approaches to human interactions and other pursuits are not given equitable standing in social analysis and practice.  Feminism seeks not only to explain historical and present-day phenomena, but to foster changes in politics, economics and social interactions.  Areas of investigation have included a focus on understanding the reasons for the devaluing of women’s contributions to the world and new ways to use feminist thinking to improve the lives of women.  While all Feminists agree that women should be brought into positions of power -– in all civilian and military institutions –- they differ in assessing the consequences of such a major change, should it occur.  While some Feminist theorists (usually called “Liberal Feminists”) hold that women in powerful positions make decisions and exercise power in ways that are essentially the same as men, others (“Difference Feminists”) contend that traditional Realist and Liberal IR theories reflect male-centered descriptions of aggressive states controlled by men, and that that the world might well become a less violent place if women had greater power in international affairs.

  • Andermahr, Sonya, Terry Lovell, and Carol Wolkowitz, eds. A Glossary of Feminist Theory. New York: Edward Arnold, 2000.
  • Butler, Judith P. Gender Trouble: Feminism and the Subversion of Identity. New York: Routledge, 1990.
  • Enloe, Cynthia. Bananas, Beaches and Bases: Making Feminist Sense of International Politics. London: Pandora Press, Harper/Collins, 1989.
  • Tickner, J. Anne. Gendering World Politics: Issues and Approaches in the Post-Cold War Era. New York: Columbia University Press, 2001.


Text provided by Professor Patrick Thaddeus Jackson and his students, School of International Service, American University