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9.2 Theories of International Relations

PLEASE NOTE: This book is currently in draft form; material is not final.

Learning Objectives

In this section you learn about:

  1. Realism, liberalism, constructivism, feminism and neo-Marxism as ways of explaining international relations.
  2. Considering other factors to explain why states behave the way they do.

The study and practice of international relations has led international relations scholars to suggest different ways that states might and should behave with regard to their neighbors around the world.


RealismThe approach to international relations theory that says that states must look out for their own interests first, and that military and economic power are the keys to security. suggests that states should and do look out for their own interests first. Realism presumes that states are out for themselves first and foremost. The world is therefore a dangerous place; a state has look out for No. 1 and prepare for the worst. When George W. Bush convinced the U.S. Congress that he should send in U.S. soldiers into Iraq in 2003 and take out Saddam Hussein, this was realism in action. Realism suggests that international relations is driven by competition between states, and states therefore do and should try to further their own interests. What matters, then, is how much economic and especially military power a state has. When your neighbor misbehaves, you can’t call the police.

Classical realists say this is just human nature. People, by nature, are at some level greedy and insecure and behave accordingly. So even if you’re not greedy and insecure, you have to behave that way, because that’s the game. Structural realists say it’s more about how the world is organized—an anarchic system creates the Hobbesian state of nature, referring to the 16th century English philosopher who justified the existence of the state by comparing it to a somewhat hypothetical “state of nature,” a war of all against all. So states should seek peace, but prepare for war.

This tends to make national security look like a zero-sum game: Anything I do to make myself more secure tends to make you feel less secure, and vice versa. A realist might counter that a balance of power between states in fact preserves the peace, by raising the cost of any aggression to an unacceptable level.

Realists argue that war, at some point, is inevitable. Anarchy persists, and it isn’t going away anytime soon.


LiberalismA theory of international relations that says that cooperation is possible to build global security. suggests in fact states can peacefully co-exist, and that states aren’t always on the brink of war. Liberal scholars point to the fact that despite the persistence of armed conflict, most nations are not at war most of the time. Most people around the world don’t get up and start chanting “Death to America!” and trying to figure out who they can bomb today. Liberalism argues that relations between nations are not always a zero-sum game. A zero-sum game is one in which any gain by one player is automatically a loss by another player. My gains in security, for example, don’t make you worse off, and your gains in anything don’t make me worse off. Liberal theory also points to the fact that despite the condition of anarchy in the world, most nations are not at war, most of the time. So the idea that international relations must be conducted as though one were always under the threat of attack isn’t necessarily indicative of reality.

There are different flavors of liberalism. Liberal institutionalismThe theory that world and regional structures such as the United Nations can be used to create global security. puts some faith in the ability of global institutions to eventually coax people into getting along as opposed to going to war. Use of the United Nations, for example, as a forum for mediating and settling dispute, will eventually promote a respect for the rule of international law in a way that parallels respect for the law common in advanced democracies. Liberal commercialismThe idea that economic growth and trade ties between states can foster global security. sees the advance of global commerce as making less likely. War isn’t actually very profitable for most people, and it really isn’t good for the economy. Liberal internationalismThe belief that as more states become democracies, war will be less likely to occur. trades on the idea that democracies are less likely to make war than are dictatorships, if only because people can say no, either in legislatures or in elections. Consider that public protest in the U.S. helped end U.S. involvement in Vietnam—that kind of thing doesn’t always happen in non-democratic states.Although it can. Argentina’s misadventures in Las Malvenas—the Falkland Islands—led to protests that brought down a longstanding military dictatorship and restored democracy to the nation in 1982. Together, these three are sometimes called the Kantian triangleImmanuel Kant’s belief that the combination of liberal institutionalism, commercialism and internationalism together will produce a more stable, prosperous world., after the German philosopher Immanuel Kant (1724–1804), who outlined them in a 1795 essay, Perpetual Peace.

Figure 9.1 [To Come] Prisoner’s Dilemma Chart

The liberal argument that states can learn to get along is somewhat supported by the work of Robert AxelrodRobert Axelrod, The Evolution of Cooperation. New York: Basic Books, 2006., who used an actual experiment involving a lot of players and the prisoner’s dilemma game to show how people and perhaps states could learn to cooperate. The prisoner’s dilemma is a fairly simple game that is useful for understanding various parts of human behavior. In this game, you have two players, both prisoners. Each player has two choices: Defect to the authorities and rat out the other player in exchange for a reduced sentence, or cooperate with the other player and go free. If the players each defect they get 1 point apiece; if they cooperate they get 3 points apiece. If, however, one player cooperates and the other defects, the defector gets 5 points and the cooperator gets zero. Given that set of constraints, in a realist world, both players defect and score only 1 point each. The best result would be for both to cooperate, go free, and generate the most points between them. In the Axelrod experiment, the game was iterated or repeated, so that in a round-robin featuring dozens of players, each player played the other player multiple times. The players were all notable game theorists, and each devised a particular strategy in an attempt to win the game. What Axelrod found was the player in his experiment who used a strategy called “tit-for-tat” won. Tit-for-tat simply began by cooperating, and then did whatever the other player did last time in the next round. In a repeated game, which certainly describes relations between states, players eventually learned to cooperate. Axelrod cites real world examples of where this kind of behavior occurred, such as the German and Allied soldiers in the trenches of World War I, who basically agreed at various times not to shoot each other, or to shell incoming shipments of food. As the soldiers came to understand that they would be facing each other for some time, refraining from killing each other meant that they all got to live.


ConstructivismThe international relations theory that suggests that people create their own reality, making the decision to go to war or remain at peace a matter of choice. is another and also interesting way of looking at international relations. It may tell us more about why things are happening the way they do, but somewhat less about what we should do about it. Constructivism argues that culture, social structures and human institutional frameworks matter. Constructivism relies in part on the theory of the social construction of reality, which says that whatever reality is perceived to be, for the most part people have invented it.Of course, if the theory were entirely true, then the very idea of the social construction of reality would also be socially constructed, and therefore potentially untrue. To the extent that reality is socially constructed, people can make choices. Hence the constructivist argument is, in part, that while the world system is indeed a form of anarchy, that does not demand a realist response to foreign policy. People can choose to otherwise. So constructivists might argue that the end of the Cold War between the U.S. and the Soviet Union was at least in part a decision by Soviet President Mikhail Gorbachev to change his thinking. He attempted then to ratchet down tensions with the U.S., and to liberalize Soviet society.Bova, 2012, p. 26. The fact that the Soviet Union promptly disintegrated doesn’t change that.

2.4 Combining theories to explain: The Cuban missile crisis

Although constructivism can be a bit mushy, some clear versions of it are quite interesting and useful in helping to understand why states behave the way they do. Realism tends to treat states as single, rational actors—as though the state were a single being, behaving in a consistent fashion with a constant eye to its own interest. As detailed by the scholar Graham AllisonGraham Allison, Essence of Decision, 1971., the rational actor model of analysis sees states nearly as single organisms, pursuing policies with some planning and coherence. Allison used the 1963 Cuban missile crisis, in which the United States and the Soviet Union nearly came to blows over the Soviets’ efforts to put nuclear-armed missiles in Cuba, to explain how other factors could explain why states behave the way they do. Allison suggests two other models. In the organizational process model, the regular behavior and processes of government agencies (bureaucracies) tends to dictate how and why things happen in government. So, for example, one of the ways in which U.S. officials were able to figure out that the Soviets were building missile sites was from aerial reconnaissance and satellite photos of the sites. Despite the fact that the Soviets were trying to keep the missiles a secret, so they could be set up and ready to go if the Soviets should have to confront the U.S. in anyway, the sites they were building looked just like all the Soviet missile sites they’d ever built.

In the governmental politics model, internal political struggles can lead to decisions that may at least be questionable. In this case, Soviet President Nikita Khruschev may have been pushed by internal political forces to put missiles in Cuba. President John F. Kennedy faced internal pressure for air strikes on the Soviet sites in Cuba, but resisted them.

In the end, the two sides were able to negotiate their way out of the standoff and ratchet down the rhetoric. The Soviets pulled the missiles out of Cuba; the U.S. pulled missiles out of Turkey—like Cuba for the U.S., right on the Soviets’ doorstep—and promised not to invade Cuba. What’s also useful and interesting about Allison’s work is that it shows how using different theories together can explain why states behave the way they do. Putting missiles in Turkey and Cuba was a realist approach to international affairs. A constructivist view can tell us why things happened the way they did: The culture and politics of the U.S. and the Soviet Union led them to make decisions, and respond to each other’s decisions, in ways that can’t be viewed as entirely rational. And, finally, the solution came from a somewhat liberal approach to policy: Sit down, talk it out, reach an agreement and pull back from the brink. Although in succeeding decades where the missiles were placed became less of an issue, as each side developed weapons that could hit any spot on the globe from anywhere else, despite all the weapons, nobody fired a shot. Despite more than five decades of nuclear tension, threats and military buildup, the world failed to blow itself up.


Realism, liberalism and constructivism may be the three most prominent theories of international relations, but they are by no means the only ones or the most important. Feminist scholars look at international relations through the prism of gender relations, noting that for much of human history, women have been relegated to a sideline role in politics and government. This isn’t wise: More than half the people in the world are women. Nonetheless, males have dominated both the study and practice of international relations, but feminist scholars note that women’s roles as wives, mothers and workers have made all of that possible. Also, a female perspective on foreign policy might be different. Feminist theoryA body of theory that seeks to understand global politics through the prism of gender issues. sometimes argues that having more women in positions of power could change things, as women may be more likely to believe peace through international cooperation is possible.

Feminist international relations theory has variants, of course. Liberal feminism wants to ensure that women have the same opportunities in society as do men, so that means liberal in the broader sense of general support for democratic capitalism. Critical feminism, on the other hand, sees capitalism as the source of women’s oppression, and seeks to create new structures for society. Cultural or essentialist feminism stresses the differences in how women view and think about the world. It argues that women’s approach to the world would be more likely to bring peace and avoid conflict.

As usual, there’s probably some kernel of truth in all of these ideas, and places where we could find cases that contradict these notions. Clearly, for example, women tend to be less involved in violent crime, and women in some parts of the world are being sold into slavery and prostitution, where their lives are largely controlled by men. On the other hand, it was a female politician, former British Prime Minister Margaret Thatcher, who marshaled her country’s military to go to war with Argentina and reclaim the Falkland Islands in 1982. But while history is full of valiant female warriors and strong leaders—from the Trung sisters and Trieu Thi Trinh of Vietnam, to Joan of Arc, and Queen Elizabeth I—they are much less common than are men famous for their conquering exploits. And the women warriors, generally, are famous for having defended their homelands as opposed to conquering somebody else’s. While some men have felt threatened by the rise of feminism in the last 60 years, it really is an opportunity to look at the world in a slightly different way, perhaps shedding some light on why things happen the way they do.


Neo-Marxists look at international relations through the perspective of our old friend Karl Marx. Remember that Marx saw the world in terms of its productive relations, so that the way in which we organize production determines social and political relations as well. Neo-Marxist theoryAn application of Marxist principles to the understanding of global politics, in particular how the nature of production—capitalism—may drive states to act toward each other in certain ways. applies this to international relations, and tends to argue that capitalism drives states to compete and attempt to dominate each other.

For example, under the variant known as Marxism-Leninism, named after the Russian revolutionary leader, Vladimir Ilyich Lenin (1870–924), world relations are really defined by the desire for industrial nations to develop both sources of raw materials and markets for finished products (what Lenin called the core and the periphery). Lenin was writing at a time when most of Africa had been carved into colonies by the European powers, and the British Empire still stretched from Africa to India to Hong Kong, so there was some evidence for what he was saying. The collapse of the Soviet empire and China’s turning away from purely Marxist economics has taken some of the steam out of the Marxian railroad of history, and we may not agree with Marx and Lenin’s suggestion that a socialist dictatorship is a necessary step on the road to nirvana. But it could be wrong to completely reject their analysis. Economic problems and conflicts do continue to inform international relations, and states do continue to try to acquire raw materials as well as markets for finished goods. China, for example, is investing heavily in Africa to lock up supplies of minerals for its growing manufacturing sector. The Chinese apparently aren’t always the best employers. To the extent that they mistreat African workers, the states where this happens will face the competing demands of a big country that is paying them a lot of money for resources, and the needs of its own citizens who work for the Chinese.

Neo-Marxists might point to this an example of where liberal commercialism is really just the capitalist class protecting its own. China is nominally still a communist state, but its economic system is really much more a sort of state-sponsored capitalism. Capitalism, Neo-Marxists argue, in its relentless quest for rising profits, leads to the degradation and impoverishment of workers. The realist explanation of U.S. policy with regard to Central America is that the U.S. propped up right-wing dictatorships there because they opposed communism. The other explanation was that U.S. commercial interests, such as the United Fruit Company, pushed to maintain their stranglehold on the banana industry. This helped lead, for example, to a CIA-sponsored coup in Guatemala 1954. The company had convinced the U.S. government that the democratically elected Guatemalan president was pro-Soviet. What is known for sure is that he was promising to redistribute land to Guatemalan peasants, which would have threatened the company’s monopoly on the banana trade.

In the view of neo-Marxist analysis, the Cold war was about the threat to U.S. business interests. The same would be true for the first and second Gulf Wars, with the U.S. fighting Iraq in part to preserve access to Middle Eastern oil. The United States intervened when Iraq invaded Kuwait much more quickly than it intervened in the former Yugoslavia, when Serbs were killing Bosnian Moslems in much greater numbers than Iraqis were killing Kuwaitis. Neo-Marxism also is realist in its orientation, since it presumes that conflict and potential between states is the reality of international affairs. But in their eyes, that conflict is driven by the conflict between business interests and workers.

Combining Theories to Explain: Mexico and the Drug Wars

Let’s look at these perspectives using Mexico as an example. Many of Mexico’s foreign policy issues involve the United States. The U.S. is Mexico’s biggest trading partner; Mexican workers in the U.S. send back a lot of money to their families still in Mexico; and U.S. drug policy has helped lead the Mexican government into an ongoing war with drug lords. That in itself raises a question: Why does Mexico persist in fighting the drug war when drug consumption is a much bigger problem for the United States than it is for Mexico?

From a realist perspective, Mexico is not in a position to go to war with the U.S., so working with the U.S. seems a much more likely alternative. As Mexico’s overall economy is so dependent on sales to and from the U.S., Mexico will do what it can to protect and preserve an open trading relationship between the two nations. A liberal perspective might suggest that Mexico put pressure on the U.S. to address its own consumption problem, while continuing efforts to bring the drug lords to heel. A constructivist approach might suggest that the real problem for Mexico is poverty and the disparity of wealth in the country; it is generally not rich people who go out and decide to sell illegal drugs. It might also suggest that Mexico’s leaders can and should make choices that differ from what realism or liberalism might suggest. A feminist analysis might suggest that Mexico’s somewhat patriarchal society leads it to overlook more peaceful avenues to solving the problem. A neo-Marxist take on it all would suggest that the capitalist nature of Mexico’s economy virtually ensures an unequal distribution of wealth, leading the poor to seek other means of empowerment, and the rich to seek to maintain the system that helped them become rich in the first place. There may be some truth to all of these ideas; you will have to decide what makes sense to you.

Key Takeaways

  • Realism suggests that because of the condition of anarchy in the world, the world is a dangerous place, and states should prepare accordingly.
  • Liberalism suggests that rather than focusing on war, states should seek to use diplomacy, international institutions, and commerce as ways of building peaceful relationships with other states.
  • Constructivism suggests that human institutions often influence states to make certain choices, blinding them to other foreign policy options.
  • Feminist theory looks at international relations with an eye to gender relations, stressing both the historical role and the potential role women can play in foreign policy.
  • Neo-Marxist theory suggests that productive relations—capitalism—causes states to compete with each other for scarce resources, negatively affecting workers in the process.


  1. In 2001, following 9/11, the U.S. invaded Afghanistan. Which theory of international relations would account for this action? Using the other theories, what else might have been done instead?