Word of the Week: Norms

Alexander VI: the normative Pope? (Creative Commons)

Traps and Norms

In previous posts, I have tried to investigate the underlying explanation for the Thucydides trap, or the hypothesis that, when a rising power confronts a ruling power, war becomes quite probable. This week, I ask which theory of international relations offers the best explanation for one particular case of peace enduring, despite the fact that a rising power (Spain) confronted a ruling power (Portugal) in the late 15th century AD. This is one of the Belter Center's 16 examples of the Thucydides trap. I find that social norms appear to play a part in explaining why the Thucydides trap did not spring in this particular case. 

Norms are patterns of behaviour. They have a descriptive element and a prescriptive element. One the one hand, norms describe patterns of behaviour, e.g. the respect that European states demonstrated for the Pope. On the other hand, norms prescribe patterns of behaviour, e.g. the respect that European states thought they ought to demonstrate for the Pope. Employing the constructivist theory of international relations, I argue that norms restrained the warlike tendencies of the Thucydides trap in the late 15th century. Nevertheless, there are many other possible explanations for why peace endured between Spain and Portugal against the odds, which I shall look at shortly. But first, before I look at the explanation for peace between Portugal and Spain, it's worth briefly describing how close Portugal and Spain got to war, and what they did to avoid it.

Portugal and Spain

In the late 15th century, Portugal, the 'ruling power' (according to Professor Allison's schema) began to feel threatened by the 'rising power' that was the Catholic monarchy of Ferdinand and Isabella, who had in 1469 united the crowns of Castile and Aragon. Since the days of Henry the Navigator, the mid-15th century Portuguese prince with exploratory ambitions, Portugal had aspired to be the world's dominant sea power. But now its neighbour was on the rise. In 1492, Ferdinand and Isabella completed their reconquest of the final emirate of the Iberian peninsula - Granada. That same year, Christopher Columbus reached the New World in 1492 with Spanish backing, after being spurned by Portuguese King John II. The balance of power 'changed almost overnight', and Portugal and Spain were set to fall into Thucydides's timeless trap.

However, the trap did not spring, and peace endured between Portugal and Spain. In 1494, Pope Alexander VI helped negotiate the Treaty of Tordesillas between Spain and Portugal, giving Portugal access to India and Africa whilst giving Spain access to most of the Americas, as the dividing line between the Spanish and Portuguese spheres of influence was the 46th meridian. Generally, lands discovered west of the meridian were to be Spanish, whereas lands discovered east of the meridian were to be Portuguese. It turned out that Portugal had pulled the short straw and got the worse end of the deal. Nevertheless, it provided the Portuguese with some comfort that the Spanish would recognise their territorial rights, allowing both powers to remain comfortable with their respective spheres of conquest.

Explaining the peace

How was the Thucydides trap avoided? This is difficult for the offensive realist, since one would presume that, if Spain really wanted to become hegemonic at sea, it would want to displace Portuguese power totally rather than reaching a compromise. Perhaps for the defensive realist the Treaty of Tordesillas makes sense, as it clearly delineated the limits of Spanish power, thus making Portugal comfortable that the balance of power remained in equilibrium. Thus the theory of  defensive (structural) realism offers the more convincing realist case on why the Thucydides trap did not have the effects that it had on Athens and Sparta in the 5th century BC. Perhaps what makes realism most convincing is that King John II was unprepared for another war with Spain.

But structural realism only looks at part of the picture.  Indeed, Portugal and Spain were trying to enhance their security in the Treaty of Tordesillas. But they were also trying to exploit the new world for prestige, and Tordesillas was not just a security treaty but also a 'charter of empire', allowing each power to go about conquering foreign lands unhindered (Disney, 2009). This supports classical realism, since prestige was more important than power in preventing the descent to war. 

Social constructivism has some backing. Spain was exhausted from its conquest of Granada and fearful of a repetition of the Wars of the Castilian Succession of 1475 - 79. This made Spain wary of war, due to its internal inhibitions and sentimental constraints on going to war again. Perhaps Isabella and Ferdinand thought that they could not justify yet another protracted war to their people. Nevertheless, this idea is, in the end, a flawed one: from 1500 to 1504, Spain was fighting with France for control of Naples, which was a fight that Spain won. Spain was, therefore, not prepared to stay at peace for the sake of peace. More realistic is the final possibility, from societal constructivism.

According to societal constructivists, like classical realists, inter-state sociology is important. Ideas such as prestige, respect, extravaganza and magisterial authority are far more significant than money, resources and power according to societal constructivists. The fact is that the international society of the time was oriented around papal authority. As such, when Alexander VI demanded a settlement, Spain and Portugal felt compelled, as fellow Catholic powers, to conform to the demands of their international society. They wanted to be good Christian members of Christendom, so did what they could to avoid war. The norm of Christian behaviour, in the end, may have been what drove Portugal and Spain to unite. 

As economic interdependence was not at its heights in the 15th century, and as neither Portugal nor Spain was democratic, the liberal theories of economic interdependence and democratic peace can be brushed aside. Therefore, on balance, the strongest three theories emerging from this case are:

Defensive (structural) realism;

Classical realism;

Societal constructivism.

Indeed, these three theories can be complementary, and no one of them need take precedence over the others. The material factors underpinning defensive realism, for instance, may be compatible with the sociological take of constructivists. Both survival and ideas were on the agenda of Spain and Portugal, suggesting that defensive realism, classical realism and societal constructivism can all offer lessons for explaining Thucydides's trap. 

Restraints on the trap

The norms of prestige and good behaviour, seen through these last two theories, were perhaps, therefore, the most important causes of peace in the Iberian peninsula. This means that the Thucydides trap, at least in this case, can be restrained by circumstances in which 

(a) war is unfeasible or unwinnable in the perception of both sides, 

(b) war risks decreasing, rather than increasing, the prestige of either state, or

(c) international society is structured in such a way that war would violate fundamental norms of good behaviour.

Which one of these circumstances has the greatest effect on restraining the Thucydides trap is a subject for future posts, when I hope to look at some of the Belfer Center's other case studies. As Professor Allison's team does not put immediate emphasis on theories such as constructivism, I hope that my analysis provides a broader look at what the mechanisms are for restraining the Thucydides trap. Providing an explanation for the age-old trap perhaps might prove useful for policymakers, who must avoid it ensnaring the United States and China. The alternative, if the historical record is reliable, is war.

References

Disney, A.R. (2009), A history of Portugal and the Portuguese empire, Cambridge: Cambridge University Press.

Harvard Thucydides’s Trap Project (2015 onwards), ‘Thucydides’s Trap Case File’. Available online at: http://www.belfercenter.org/thucydides-trap/resources/case-file-graphic

Word of the Week: Explanations

Figure 1: Professor John Mearsheimer, whose theory may explain the Thucydides trap (Creative Commons)

Explaining Thucydides

My post entitled Word of the Week: Trap discussed Graham Allison's (2015) concept of the Thucydides trap. Derived from classical Greek historian Thucydides, this states that  when a rising power confronts a ruling power, the probability of war is raised significantly. In subsequent posts, I'll consider some examples given by Allison's team at the Belfer Center. When I do so, a central question will be: why did war occur or not occur in this case? What, in other words, are the conditions for the Thucydides trap springing, and what are the trap's causal mechanisms that actually lead to war? The Thucydides's trap gives a hypothesis, or a relationship between (a) a rising power confronting a ruling power and (b) war. But it does not give an explanation for why there is such a relationship. Theory comes in two parts: (1) hypothesis-testing and (2) explaining the hypothesis (Brown & Ainley, 2009: 203). In this post, I examine the broad theories of international relations, in the hope that one or more might provide the explanation we need. 

Different theories, different explanations 

The three main theories of international relations can be subdivided as follows (a couple of these terms are my own):

(1)  Liberalism

a.    Economic interdependence

b.    Democratic peace

(2)  Realism

a.    Classical

b.    Structural

                        i.    Defensive

                        ii.   Offensive

(3)  Constructivism

a.    Social

b.    Societal

Figure 2: Three theories of international relations

I'd like to analyse each of these theories in turn, asking what they can tell us, if anything, about the possible explanations for the Thucydides trap.

International relations as a formal discipline kicked off in the 20th century with the theory known as liberalism (Brown & Ainley, 2009). The likes of Norman Angell claimed that 'Europe's Optical Illusion' was its unfounded belief in the utility of war. For Angell, the economic interdependence in Europe had made war redundant. Economic prosperity and interconnectedness, for Angellian liberals, could lead to peace. Optimism was at its greatest in the lead-up to the First World War (Coker, 2015). This notion of economic interdependence as the cornerstone of liberalism has some statistical grounding (Mousseau, 2000). For liberals of this persuasion, war between great powers is to be explained by a collapse of economic interdependence or by the world economy in general, which might be their way of framing the Thucydides trap.

After the First World War broke out, a second breed of liberalism began, in order to account for the sometime breakdown of peace in apparently prosperous times. For President Woodrow Wilson, America's declaring war on Imperial Germany on 6 April 1917 was intended to create a post-war world 'safe for democracy'. Wilson's dream was Immanuel Kant's, of an international society of peaceful democracies (Russett, 1995; Kant, 1970 [1795]). This is known as the democratic peace thesis. But that vision nearly collapsed with the Second World War, as the apparently pro-democracy League of Nations was found futile in the face of fascism. For democratic peace liberals, therefore, the Thucydides trap might be framed as a circumstance where two states clash due to their undemocratic values. At the very least, even if just one state is nondemocratic, then the chance of war war between the two states vastly increases. 

Nevertheless, after the Second World War shook liberal optimism, a school of thought known as realism came to the rescue. Realists believe that the world is anarchic. So states have no choice but to behave in a rational-egoistic, or calculating and selfish, way. Realist thinkers range from Hans Morgenthau and E.H. Carr to Kenneth Waltz and John J. Mearsheimer. What unites them is a common belief in the primacy of survival above all other interests of a state. But there's a key division to be made between classical realists and structural realists. 

While classical realists such as Morgenthau (1948) emphasise the importance of human nature in creating Machiavellian world politics, structural realists look not to human agents but instead to the supra-human structures of world politics. For structural realists, anarchy is what drives rational egoism, whereas for classical realists human nature is what makes states so provocative. For classical realists, the rise of Athens and similar powers is to be explained in terms of the personal ambition of leaders such as Pericles. However, for structural realists, the Thucydides trap can be framed as a structural contest between two competing powers, rather than a personality contest. 

Nevertheless, even structural realists are divided on what the result of this rational egoism is: perhaps states merely seek to protect themselves by using defensive measures (defensive realism), or perhaps they seek to actively dominate their regions, following John J. Mearsheimer's dictum that it is 'Better to Be Godzilla than Bambi' (offensive realism) (Mearsheimer & Brzezinski, 2009). Defensive realists such as Kenneth Waltz would tend to emphasise an upending of the balance of power as the cause of the Thucydides trap. Offensive realists, on the other hand, would argue that superpowers clash when they both want to become hegemonic, or dominant. The mutually exclusive aims of great powers are what would precipitate the Thucydides trap for an offensive realist. 

However, it has been argued that the realist orthodoxy is being reshaped by constructivism (Brown & Ainley, 2009). Alexander Wendt has taken a lead in promoting social constructivism, or the theory that both liberal and realist ideas - such as, say, the democratic peace and anarchy - are socially constructed. Wendt points out that that there is 'no such thing as a "logic of anarchy" per se', since anarchy literally means 'without rule', so it is 'nothing'. As 'nothings cannot be structures', Wendt argues that anarchic systems are 'a function of social structures, not anarchy' (Wendt, 2010: 308 - 309). Therefore, anarchy is not a structure, as the realists maintain. Rather, 'anarchy is what states make of it' (ibid.: 377). Thus social constructivists such as Wendt believe that, whether the world is liberal or realist in character, at the end of the day social structures take precedence over realist structures. Therefore, if the Thucydides trap has any truth for the social constructivist, it would be due to a perception of an inevitable war, whether or not such a perception is objectively valid. 

Constructivists, unlike liberals and realists, tend to agree on some key principles. They agree, for instance, on the primacy of norms and ideas over material factors such as raw, unencumbered anarchy. Nevertheless, although they do not differ much from social constructivists, what I term societal constructivists put emphasis on subtly different phenomena. According to societal constructivism, commonly known as 'English School' constructivism, there is evident societal variation in traditions of anarchy. Some international societies, for instance, tend to lack anarchy, such as the Roman Empire and Napoleon's dominions, whereas in other cultures, such as the ancient Sumerian and Hellenistic (Greek) societies, anarchy is the cornerstone of social interaction at the state level (Watson, 2009). 

Societal constructivists essentially agree with the social constructivists that anarchy is what states make of it. But they emphasise the ability of systems to change and reform over time, and they therefore take a more historical look at the evolution of international society. In that respect, societal constructivists have many similarities with classical realists, who draw much influence from thinkers ranging from Thucydides himself to Machiavelli. Societal constructivists, in turn, are influenced by Hugo Grotius (Heywood, 2015), as well as by David Hume (Mayall, 2000). For societal constructivists, the Thucyides trap might be triggered in a society in which violence is the norm, but could equally be avoided in a society in which peace rewards states with more respect and appreciation than war. 

So, having gone through the sub-theories and noting that they can count as theories in themselves, it's worth giving an alternative version of Figure 2:

(1) Economic interdependence liberalism

(2) Democratic peace liberalism

(3) Classical realism

(4) Defensive (structural) realism

(5) Offensive (structural) realism

(6) Social constructivism

(7) Societal constructivism

Figure 3: Seven (sub-)theories of international relations

Next week, I'll apply these theories to the Belfer Center's first case study of the Thucydides trap: Portugal and Spain in the late 15th century. I find that liberalism doesn't quite work in explaining why the Thucydides trap didn't spring and peace endured. Defensive realism and the constructivist theories seem to be the most convincing in this case. Ultimately, looking at cases as old as the Portuguese-Spanish rivalry is vital in order to check the possible explanations for the trap, which may prove to be the defining issue of our time. After all, the consequences of sleepwalking into the trap, and the ensuing US-Chinese war, may prove catastrophic (Coker, 2015).  

References

Angell, Norman (1909), 'Europe's optical illusion', London: Simpkin, Marshall, Hamilton, Kent.

Brown, Chris, & Ainley, Kirsten (2009), Understanding international relations, Basingstone: Palgrave Macmillan.

Coker, Christopher (2015), The improbable war: China, the United States & the logic of great power conflict, London: Hurst & Company.

The Economist (2017), 'Lessons from the first world war', 6 April. Available online at: http://www.economist.com/news/united-states/21720275-and-why-america-should-remember-them-now-lessons-first-world-war
Harvard Thucydides’s Trap Project (2015 onwards), ‘Thucydides’s Trap Case File’. Available online at: http://www.belfercenter.org/thucydides-trap/resources/case-file-graphic

Heywood, Andrew (2015), Global politics, New York: Palgrave Macmillan.
Kant, Immanuel (1970), Kant’s political writings, Oxford: Oxford University Press.

Brzezinsk, Zbigniew, & Mearsheimer, John J. (2009), ‘Clash of the titans’, Foreign Policy, October 22. Available online at: http://foreignpolicy.com/2009/10/22/clash-of-the-titans/

Mayall, James (2000), World politics: Progress and its limits, Cambridge: Polity Press.

Morgenthau, Hans (1948), Politics among nations: The struggle for power and peace, New York: Alfred P. Knopf.

Mousseau, Michael (2000), 'Market prosperity, democratic consolidation, and democratic peace', Journal of Conflict Resolution, 44(4), 472-507.

Russett, Bruce (1995), Grasping the democratic peace: Principles for a post-Cold War world, Princeton, NJ: Princeton University Press.

Tsygankov, Andrei P., & Tarver‐Wahlquist, Matthew (2009), 'Duelling honors: Power, identity and the Russia–Georgia divide', Foreign Policy Analysis, 5(4), 307-326.

Watson, Adam (2009), The Evolution of International Society: A Comparative Historical Analysis Reissue with a new introduction by Barry Buzan and Richard Little, Routledge.

Wendt, Alexander (2010 [1999]), Social Theory of International Politics, Cambridge: Cambridge University Press.

Word of the Week: Norms #1

Alexander VI: the normative Pope? (Creative Commons)

Traps and Norms

In previous posts, I have tried to investigate the underlying explanation for the Thucydides trap, or the hypothesis that, when a rising power confronts a ruling power, war becomes quite probable. This week, I ask which theory of international relations offers the best explanation for one particular case of peace enduring, despite the fact that a rising power (Spain) confronted a ruling power (Portugal) in the late 15th century AD. This is one of the Belter Center's 16 examples of the Thucydides trap. I find that social norms appear to play apart in explaining why the Thucydides trap did not spring in this particular case. 

Norms are patterns of behaviour. They have a descriptive element and a prescriptive element. One the one hand, norms describe patterns of behaviour, e.g. the respect that European states demonstrated for the Pope. On the other hand, norms prescribe patterns of behaviour, e.g. the respect that European states thought they ought to demonstrate for the Pope. Employing the constructivist theory of international relations, I argue that norms restrained the warlike tendencies of the Thucydides trap in the late 15th century. Nevertheless, there are many other possible explanations for why peace endured between Spain and Portugal against the odds, which I shall look at shortly. But first, before I look at the explanation for peace between Portugal and Spain, it's worth briefly describing how close Portugal and Spain got to war, and what they did to avoid it.

Portugal and Spain

In the late 15th century, Portugal, the 'ruling power' (according to Professor Allison's schema) began to feel threatened by the 'rising power' that was the Catholic monarchy of Ferdinand and Isabella, who had in 1469 united the crowns of Castile and Aragon. Since the days of Henry the Navigator, the mid-15th century Portuguese prince with exploratory ambitions, Portugal had aspired to be the world's dominant sea power. But now its neighbour was on the rise. In 1492, Ferdinand and Isabella completed their reconquest of the final emirate of the Iberian peninsula - Granada. That same year, Christopher Columbus reached the New World in 1492 with Spanish backing, after being spurned by Portuguese King John II. The balance of power 'changed almost overnight', and Portugal and Spain were set to fall into Thucydides's timeless trap.

However, the trap did not spring, and peace endured between Portugal and Spain. In 1494, Pope Alexander VI helped negotiate the Treaty of Tordesillas between Spain and Portugal, giving Portugal access to India and Africa whilst giving Spain access to most of the Americas, as the dividing line between the Spanish and Portuguese spheres of influence was the 46th meridian. Generally, lands discovered west of the meridian were to be Spanish, whereas lands discovered east of the meridian were to be Portuguese. It turned out that Portugal had pulled the short straw and got the worse end of the deal. Nevertheless, it provided the Portuguese with some comfort that the Spanish would recognise their territorial rights, allowing both powers to remain comfortable with their respective spheres of conquest.

Explaining the peace

How was the Thucydides trap avoided? This is difficult for the offensive realist, since one would presume that, if Spain really wanted to become hegemonic at sea, it would want to displace Portuguese power totally rather than reaching a compromise. Perhaps for the defensive realist the Treaty of Tordesillas makes sense, as it clearly delineated the limits of Spanish power, thus making Portugal comfortable that the balance of power remained in equilibrium. Thus the theory of  defensive (structural) realism offers the more convincing realist case on why the Thucydides trap did not have the effects that it had on Athens and Sparta in the 5th century BC. Perhaps what makes realism most convincing is that King John II was unprepared for another war with Spain.

But structural realism only looks at part of the picture.  Indeed, Portugal and Spain were trying to enhance their security in the Treaty of Tordesillas. But they were also trying to exploit the new world for prestige, and Tordesillas was not just a security treaty but also a 'charter of empire', allowing each power to go about conquering foreign lands unhindered (Disney, 2009). This supports classical realism, since prestige was more important than power in preventing the descent to war. 

Social constructivism has some backing. Spain was exhausted from its conquest of Granada and fearful of a repetition of the Wars of the Castilian Succession of 1475 - 79. This made Spain wary of war, due to its internal inhibitions and sentimental constraints on going to war again. Perhaps Isabella and Ferdinand thought that they could not justify yet another protracted war to their people. Nevertheless, this idea is, in the end, a flawed one: from 1500 to 1504, Spain was fighting with France for control of Naples, which was a fight that Spain won. Spain was, therefore, not prepared to stay at peace for the sake of peace. More realistic is the final possibility, from societal constructivism.

According to societal constructivists, like classical realists, inter-state sociology is important. Ideas such as prestige, respect, extravaganza and magisterial authority are far more significant than money, resources and power according to societal constructivists. The fact is that the international society of the time was oriented around papal authority. As such, when Alexander VI demanded a settlement, Spain and Portugal felt compelled, as fellow Catholic powers, to conform to the demands of their international society. They wanted to be good Christian members of Christendom, so did what they could to avoid war. The norm of Christian behaviour, in the end, may have been what drove Portugal and Spain to unite. 

As economic interdependence was not at its heights in the 15th century, and as neither Portugal nor Spain was democratic, the liberal theories of economic interdependence and democratic peace can be brushed aside. Therefore, on balance, the strongest three theories emerging from this case are:

Defensive (structural) realism;

Classical realism;

Societal constructivism.

Indeed, these three theories can be complementary, and no one of them need take precedence over the others. The material factors underpinning defensive realism, for instance, may be compatible with the sociological take of constructivists. Both survival and ideas were on the agenda of Spain and Portugal, suggesting that defensive realism, classical realism and societal constructivism can all offer lessons for explaining Thucydides's trap. 

Restraints on the trap

The norms of prestige and good behaviour, seen through these last two theories, were perhaps, therefore, the most important causes of peace in the Iberian peninsula. This means that the Thucydides trap, at least in this case, can be restrained by circumstances in which 

(a) war is unfeasible or unwinnable in the perception of both sides, 

(b) war risks decreasing, rather than increasing, the prestige of either state, or

(c) international society is structured in such a way that war would violate fundamental norms of good behaviour.

Which one of these circumstances has the greatest effect on restraining the Thucydides trap is a subject for future posts, when I hope to look at some of the Belfer Center's other case studies. As Professor Allison's team does not put immediate emphasis on theories such as constructivism, I hope that my analysis provides a broader look at what the mechanisms are for restraining the Thucydides trap. Providing an explanation for the age-old trap perhaps might prove useful for policymakers, who must avoid it ensnaring the United States and China. The alternative, if historical record is reliable, is war.

References

Disney, A.R. (2009), A history of Portugal and the Portuguese empire, Cambridge: Cambridge University Press.

Harvard Thucydides’s Trap Project (2015 onwards), ‘Thucydides’s Trap Case File’. Available online at: http://www.belfercenter.org/thucydides-trap/resources/case-file-graphic

Word of the Week: Explanations #1

Figure 1: Professor John Mearsheimer, whose theory may explain the Thucydides trap (Creative Commons)

Explaining Thucydides

As promised in my post entitled Word of the Week: Trap, I hope to consider the Belfer Center's 16 examples of the Thucydides trap. According to the logic of this trap, derived from classical Greek historian Thucydides, when a rising power confronts a ruling power, the probability of war is raised significantly. Is this true? To answer this question, I will be looking at the 16 examples given by the Belfer Center, 12 of which have resulted in war. But before I consider the examples themselves, it's worth noting that a central question for each case is why did war occur or not occur? What, in other words, are the conditions for the Thucydides trap springing, and what are the trap's causal mechanisms that actually lead to war? The Thucydides's trap gives a hypothesis, or a relationship between (a) a rising power confronting a ruling power and (b) war. But it does not give an explanation for why there is such a relationship. Theory comes in two parts: (1) hypothesis-testing and (2) explaining the hypothesis (Brown & Ainley, 2009: 203). So, if I am to ask in each case study what best explains the operation of Thucydides's trap, it is worth asking what the broad theories of international relations are, which might provide the explanation we need. To do so, it's worth considering the three main theories of international relations, which can be subdivided as follows:

(1)  Liberalism

a.    Economic interdependence

b.    Democratic peace

(2)  Realism

a.    Classical

b.    Structural

                        i.    Defensive

                        ii.   Offensive

(3)  Constructivism

a.    Social

b.    Societal

Figure 2: Three theories of international relations

The names I use for the realism's sub theories are generally true to their authors. However, the names for the sub-theories of liberalism and constructivism are not necessarily common-place. For instance, 'societal' constructivists tend to be referred to as 'English School' theorists, due to their being based at Oxford, Cambridge and London School of Economics. But my descriptions of these theories, seen below, are nevertheless as true as possible to their authors. So now, without further ado, I'd like to analyse each of these theories in turn, asking what they can tell us, if anything, of the possible explanations for the Thucydides trap.

Traps and Theory 

International relations as a formal discipline kicked off in the Twentieth Century with the theory known as liberalism (Brown & Ainley, 2009). The likes of Norman Angell claimed that 'Europe's Optical Illusion' was its unfounded belief in the utility of war. For Angell, the economic interdependence in Europe had made war redundant. Economic prosperity and interconnectedness, for Angellian liberals, could lead to peace. Optimism was at its greatest in the lead-up to the First World War (Coker, 2015). This notion of economic interdependence as the cornerstone of liberalism has some statistical grounding (Mousseau, 2000). For liberals of this persuasion, war between great powers is to be explained by a collapse of economic interdependence or by the world economy in general, which might be their way of framing the Thucydides trap.

After the First World War broke out, a second breed of liberalism began, in order to account for the sometime breakdown of peace in apparently prosperous times. For President Woodrow Wilson, America's declaring war on Imperial Germany on 6 April 1917 was intended to create a post-war world 'safe for democracy'. Wilson's dream was Immanuel Kant's, of an international society of peaceful democracies (Russett, 1995; Kant, 1970 [1795]). This is known as the democratic peace thesis. But that vision nearly collapsed with the Second World War, as the apparently pro-democracy League of Nations was found futile in the face of fascism. For democratic peace liberals, therefore, the Thucydides trap might be framed as a circumstance where two states clash due to their undemocratic values. At the very least, even if just one state is nondemocratic, then the cane of war war between the two states vastly increases. 

After the devastation of the Second World War, a school of thought known as realism came to the rescue. Realists believe that the world is anarchic. As such, states have no choice but to behave in a rational-egoistic, or calculating and selfish, way. Realist thinkers range from Hans Morgenthau and E.H. Carr to Kenneth Waltz and John J. Mearsheimer. What unites them is a common belief in the primacy of survival above all other interests of a state. But there's a key division to be made between classical realists and structural realists. 

Whilst classical realists such as Morgenthau (1948) emphasise the importance of human nature in creating Machiavellian world politics, structural realists look not to the human agents but instead to the supra-human structures of world politics. For structural realists, anarchy is what drives rational egoism, whereas for classical realists human nature is what makes states so provocative. For classical realists, the rise of Athens, and similar powers, is to be explained in terms of the personal ambition of leaders such as Pericles. However, for structural realists, the Thucydides trap is to be framed as a structural contest between two competing powers, rather than as a personality contest. 

Nevertheless, even structural realists are divided on what the result of this rational egoism is: perhaps states merely seek to protect themselves by using defensive measures (defensive realism) or perhaps they seek to actively dominate their regions, following John J. Mearsheimer's thesis that it is 'Better to Be Godzilla than Bambi' (offensive realism) (Mearsheimer & Brzezinski, 2009). Defensive realists such as Kenneth Waltz would tend to emphasise an upending of the balance of power as the cause of the Thucydides trap, if such a trap does spring. Offensive realists, on the other hand, would argue that superpowers clash when they both want to go on the offensive and become hegemonic, or dominant. The mutually exclusive aims of great powers are what would precipitate the Thucydides trap for an offensive realist. 

However, it has been argued that the realist orthodoxy is being reshaped by constructivism (Brown & Ainley, 2009). Alexander Wendt has taken the lead in promoting social constructivism, or the theory that both liberal and realist ideas - such as, say, the democratic peace and anarchy - are socially constructed. Wendt points out that that there is 'no such thing as a "logic of anarchy" per se', since anarchy literally means 'without rule', so it is 'nothing'. As 'nothings cannot be structures', Wendt argues that anarchic systems are 'a function of social structures, not anarchy' (Wendt, 2010: 308 - 309). Therefore, anarchy is not a structure, as the realists maintain. Rather, 'anarchy is what states make of it' (ibid.: 377). Thus social constructivists such as Wendt believe that, whether the world is liberal or realist in character, at the end of the day social structures take precedence over realist structures. Therefore, if the Thucydides trap has any truth for the social constructivist, it is due to a perception of an inevitable war, whether or not such a perception is valid. 

Constructivists, unlike liberals and realists, all tend to agree on key principles. They agree, for instance, on the primacy of norms and ideas over material factors such as raw, unencumbered anarchy. Nevertheless, although they do not differ much from social constructivists, what I term societal constructivists put emphasis on subtly different phenomena. According to societal constructivism, commonly known as 'English School' constructivism, there is evident societal variation in traditions of anarchy. Some international societies, for instance, tend to lack anarchy, such as the Roman Empire and Napoleon's dominions, whereas in other cultures, such as the ancient Sumerian and Hellenistic (Greek) societies, anarchy is the cornerstone of social interaction at the state level (Watson, 2009). 

Societal constructivists essentially agree with the social constructivists that anarchy is what states make of it. But they emphasise the ability of systems to change and reform over time, and they therefore take a more historical look at the evolution of international society. In that respect, societal constructivists have many similarities with classical realists, who draw much influence from thinkers ranging from Thucydides himself to Machiavelli. Societal constructivists, in turn, are influenced by Hugo Grotius, as well as David Hume (Mayall, 2000). For societal constructivists, the Thucyides trap might be triggered in a society in which violence is the norm, but could equally be avoided in a society in which peace rewards states with more respect and appreciation than war. 

So, having gone through the sub-theories and noting that they can count as theories in themselves, it's worth noting an alternative version of Figure 2:

(1) Economic interdependence liberalism

(2) Democratic peace liberalism

(3) Classical realism

(4) Defensive (structural) realism

(5) Offensive (structural) realism

(6) Social constructivism

(7) Societal constructivism

Figure 3: Seven (sub-)theories of international relations

Next week, I'll apply these theories to the Belfer Center's first case study: Portugal and Spain. I find that liberalism doesn't quite work in explaining why the Thucydides trap didn't spring and peace endured. Defensive realism and the constructivist theories seem to be the most convincing in this case. Ultimately, looking at cases as old as the Portuguese-Spanish rivalry is vital, as the Thucydides trap may prove to be the defining question of our time. After all, the consequences of sleepwalking into the trap, and the ensuing US-Chinese war, may prove lethal (Coker, 2015).  

References

Angell, Norman (1909), 'Europe's optical illusion', London: Simpkin, Marshall, Hamilton, Kent.

Brown, Chris, & Ainley, Kirsten (2009), Understanding international relations, Basingstone: Palgrave Macmillan.

Coker, Christopher (2015), The improbable war: China, the United States & the logic of great power conflict, London: Hurst & Company.

The Economist (2017), 'Lessons from the first world war', 6 April. Available online at: http://www.economist.com/news/united-states/21720275-and-why-america-should-remember-them-now-lessons-first-world-war
Harvard Thucydides’s Trap Project (2015 onwards), ‘Thucydides’s Trap Case File’. Available online at: http://www.belfercenter.org/thucydides-trap/resources/case-file-graphic

Kant, Immanuel (1970), Kant’s political writings, Oxford: Oxford University Press.

Brzezinsk, Zbigniew, & Mearsheimer, John J. (2009), ‘Clash of the titans’, Foreign Policy, October 22. Available online at: http://foreignpolicy.com/2009/10/22/clash-of-the-titans/

Mayall, James (2000), World politics: Progress and its limits, Cambridge: Polity Press.

Morgenthau, Hans (1948), Politics among nations: The struggle for power and peace, New York: Alfred P. Knopf.

Mousseau, Michael (2000), 'Market prosperity, democratic consolidation, and democratic peace', Journal of Conflict Resolution, 44(4), 472-507.

Russett, Bruce (1995), Grasping the democratic peace: Principles for a post-Cold War world, Princeton, NJ: Princeton University Press.

Tsygankov, Andrei P., & Tarver‐Wahlquist, Matthew (2009), 'Duelling honors: Power, identity and the Russia–Georgia divide', Foreign Policy Analysis, 5(4), 307-326.

Watson, Adam (2009), The Evolution of International Society: A Comparative Historical Analysis Reissue with a new introduction by Barry Buzan and Richard Little, Routledge.

Wendt, Alexander (2010 [1999]), Social Theory of International Politics, Cambridge: Cambridge University Press.