Word of the Week: Trap

Thomas Hobbes's translation of Thucydides's 'History of the Peloponnesian War' (Creative Commons)

A historical project led by Professor Graham Allison has drawn attention to a surprisingly ill-documented phenomenon: the Thucydides trap. It's a pertinent theory, since, if applied to the rise of modern-day China, it would predict a US-Chinese war. According to Ancient Greek historian Thucydides, 'It was the rise of Athens, and the fear that this instilled in Sparta, that made war inevitable.' Thucydides was referring to the Pelopponesian War, fought between the ambitious Athenians and powerful Spartans in the city-state system of Ancient Greece. After the Greco-Persian Wars of 499-449 BC, which resulted in Greek victory and Persian acquiescence, Athens concluded a peace treaty with Sparta in 445 BC. This resulted in the 'Thirty Years Peace' (which only actually lasted 14 years), dividing Greece into Athenian and Spartan spheres of influence. Adam Watson has more recently referred to this period as the 'diarchy', in which Sparta and Athens exercised joint hegemony, or dominance, over the Greek city states. However, after Athens launched its bid for unilateral, Athenian hegemony over Greece, and invaded Potidaea in 432 BC, the furious Corinthians persuaded Sparta to begin the Pelopponesian War in 431 BC. By 404 BC, the Athenians, exhausted, forfeited power to Sparta, symbolising the failure of Athens's attempt to replace Sparta. But the real cost of Athenian ambition was the war that they precipitated.

Graham Allison summarises Thucydides's account as what he calls 'the Thucydides trap'. According to this theory, war is particularly likely when a 'rising power' confronts a 'ruling power'. In Thucydides's example, Athens was the rising power and Sparta was the ruling power. Perhaps Allison's account is misleading, because, technically speaking, both Athens and Sparta were 'ruling powers' during the 14 years of peace up to the Pelopponesian War (Watson, 2009). But at least Allison is certainly right in characterising Athens as a 'rising power'. Athens, after all, was more powerful at the beginning of the Pelopponesian War than it was at the end of the Greco-Persian Wars: it controlled the Delian League of city states from the Bosphorus straits to the island of Rhodes, inspiring fear in the hearts of Spartans. Perhaps the distinction is not between 'ruling' and 'rising', but rather between the status quo power of Sparta (since it wanted to preserve the present power balance rather than changing it in Athens's favour) and the rising power of Athens. 

Whether Thucydides would have agreed or not is perhaps a matter for another day. But generally speaking, when we refer to the Thucydides trap, we are referring to one state increasing its power in such a way that the other feels compelled to respond violently. When one state rises, and the other does not want to budge, war becomes more probable. Let me summarise the Thucydides trap as follows:

1. When a rising power confronts a ruling (or status quo) power,
2. The probability of war is raised significantly.

Possibly the best objection to the theory of the Thucydides trap is that it's outdated. In the 21st century, one may argue, war between great powers has become impossible. Although I recently argued that China's rise may displace America, this does not necessarily mean that war will happen as a result of this. Perhaps circumstances have changed: it is arguable that a rising Athens is infinitely less wise than a rising China, and that a ruling Sparta is infinitely more paranoid than a ruling America. However, the evidence suggests that Thucydides would not be too out-of-place in the modern age: out of 16 cases of a rising power confronting a ruling power since the 15th century, 12 have resulted in war. All other things being equal, that means that the probability of a US-Chinese war is approximately 75%, which is quite high. Too high.

Harvard Thucydides's Trap Project (2015 onwards): table of the historical evidence for the Thucydides trap

Over the next couple of weeks, I'm going to looking at these 16 cases in more detail, asking 

if they can tell us anything about the probability of a US-Chinese war. Because if the case studies do have some relevance to the modern world, then the question is not: will the Thucydides trap spring? If Graham Allison is right, and the Thucydides trap has already sprung, then the question we really need to ask is: can America and China escape the Thucydides trap?

References

Allison, Graham (2015), ‘The Thucydides Trap: Are the US and China headed for war?’, The Atlantic. Available online at: https://www.theatlantic.com/international/archive/2015/09/united-states-china-war-thucydides-trap/406756/

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

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