By John Mearsheimer & Sebastian Rosato, UnHerd, 9/14/23

It is widely believed in the West that Russian president Vladimir Putin’s decision to invade Ukraine was not a rational act. On the eve of the invasion, then British prime minister Boris Johnson suggested that perhaps the United States and its allies had not done “enough to deter an irrational actor and we have to accept at the moment that Vladimir Putin is possibly thinking illogically about this and doesn’t see the disaster ahead”. US senator Mitt Romney made a similar point after the war started, noting that “by invading Ukraine, Mr Putin has already proved that he is capable of illogical and self-defeating decisions”. The assumption underlying both statements is that rational leaders start wars only if they are likely to win. By starting a war he was destined to lose, the thinking went, Putin demonstrated his non-rationality.

Other critics argue that Putin was non-rational because he violated a fundamental international norm. In this view, the only morally acceptable reason for going to war is self-defence, whereas the invasion of Ukraine was a war of conquest. Russia expert Nina Khrushcheva asserted that “with his unprovoked assault, Mr Putin joins a long line of irrational tyrants”, and appears “to have succumbed to his ego-driven obsession with restoring Russia’s status as a great power with its own clearly defined sphere of influence”. Bess Levin of Vanity Fair described Russia’s president as “a power-hungry megalomaniac”; former British ambassador to Moscow Tony Brenton suggested his invasion was proof that he is an “unbalanced autocrat” rather than the “rational actor” he once was.

These claims all rest on common understandings of rationality that are intuitively plausible but ultimately flawed. Contrary to what many people think, we cannot equate rationality with success and non-rationality with failure. Rationality is not about outcomes. Rational actors often fail to achieve their goals, not because of foolish thinking but because of factors they can neither anticipate nor control. There is also a powerful tendency to equate rationality with morality since both qualities are thought to be features of enlightened thinking. But this too is a mistake. Rational policies can violate widely accepted standards of conduct and may even be murderously unjust.

So what is “rationality” in international politics? Surprisingly, the scholarly literature does not provide a good definition. For us, rationality is all about making sense of the world — that is, figuring out how it works and why — in order to decide how to achieve certain goals. It has both an individual and a collective dimension. Rational policymakers are theory-driven; they are homo theoreticus. They have credible theories — logical explanations based on realistic assumptions and supported by substantial evidence — about the workings of the international system, and they employ these to understand their situation and determine how best to navigate it. Rational states aggregate the views of key policymakers through a deliberative process, one marked by robust and uninhibited debate.

All of this means that Russia’s decision to invade Ukraine was rational. Consider that Russian leaders relied on a credible theory. Most commentators dispute this claim, arguing that Putin was bent on conquering Ukraine and other countries in Eastern Europe to create a greater Russian empire, something that would satisfy a nostalgic yearning among Russians but that makes no strategic sense in the modern world. President Joe Biden maintains that Putin aspires “to be the leader of Russia that united all of Russian speakers. I mean… I just think it’s irrational.” Former national security adviser H. R. McMaster argues: “I don’t think he’s a rational actor because he’s fearful, right? What he wants to do more than anything is restore Russia to national greatness. He’s driven by that.”

But there is solid evidence that Putin and his advisers thought in terms of straightforward balance-of-power theory, viewing the West’s efforts to make Ukraine a bulwark on Russia’s border as an existential threat that could not be allowed to stand. Russia’s president laid out this logic in a speech explaining his decision for war: “With Nato’s eastward expansion the situation for Russia has been becoming worse and more dangerous by the year… We cannot stay idle and passively observe these developments. This would be an absolutely irresponsible thing to do for us.” He went on to say: “It is not only a very real threat to our interests but to the very existence of our state and to its sovereignty. It is the redline which we have spoken about on numerous occasions. They have crossed it.”

In other words, for Putin, this was a war of self-defence aimed at preventing an adverse shift in the balance of power. He had no intention of conquering all of Ukraine and annexing it into a greater Russia. Indeed, even as he claimed in his well-known historical account of Russia-Ukraine relations that “Russians and Ukrainians were one people — a single whole”, he also declared: “We respect Ukrainians’ desire to see their country free, safe, and prosperous… And what Ukraine will be — it is up to its citizens to decide.” None of this is to deny that his aims have clearly expanded since the war began, but that is hardly unusual as wars unfold and circumstances change.

It is worth noting that Moscow sought to deal with the growing threat on its borders through aggressive diplomacy, but the United States and its allies were unwilling to accommodate Russia’s security concerns. On 17 December 2021, Russia put forward a proposal to solve the growing crisis that envisaged a neutral Ukraine and the withdrawal of Nato forces from Eastern Europe to their positions in 1997. But the United States rejected it out of hand.

This being the case, Putin opted for war, which analysts expected to result in the Russian military’s overrunning Ukraine. Describing the view of US officials just before the invasion, David Ignatius of The Washington Post wrote that Russia would “quickly win the initial, tactical phase of this war, if it comes. The vast army that Russia has arrayed along Ukraine’s borders could probably seize the capital of Kyiv in several days and control the country in little more than a week.” Indeed, the intelligence community “told the White House that Russia would win in a matter of days by quickly overwhelming the Ukrainian army”. Of course, these assessments proved wrong, but even rational policymakers sometimes miscalculate, because they operate in an uncertain world.

The Russian decision to invade was also the product of a deliberative process, not a knee-jerk reaction by a lone wolf. Again, many observers dispute this point, arguing that Putin operated without serious input from civilian and military advisers, who would have counselled against his reckless bid for empire. As Senator Mark Warner, the chair of the Senate Intelligence Committee, put it: “He’s not had that many people having direct inputs to him. So we’re concerned that this kind of isolated individual [has] become a megalomaniac in terms of his notion of himself being the only historic figure that can rebuild old Russia or recreate the notion of the Soviet sphere.” Elsewhere, former ambassador to Moscow Michael McFaul suggested that one element of Russia’s non-rationality is that Putin is “profoundly isolated, surrounded only by yes men who have cut him off from accurate knowledge”.

But what we know about Putin’s coterie and its thinking about Ukraine reveals a different story: Putin’s subordinates shared his views about the nature of the threat confronting Russia, and he consulted with them before deciding on war. The consensus among Russian leaders regarding the dangers inherent in Ukraine’s relationship with the West is clearly reflected in a 2008 memorandum by then ambassador to Russia William Burns; it warned that “Ukrainian entry into Nato is the brightest of all redlines for the Russian elite (not just Putin). In more than two and a half years of conversations with key Russian players, from knuckle-draggers in the dark recesses of the Kremlin to Putin’s sharpest liberal critics, I have yet to find anyone who views Ukraine in Nato as anything other than a direct challenge to Russian interests… I can conceive of no grand package that would allow the Russians to swallow this pill quietly.”

Nor does Putin appear to have made the decision for war alone, as stories of him plotting in Covid-induced confinement implied. When asked whether the Russian president consulted with his key advisers, Foreign Minister Sergei Lavrov replied: “Every country has a decision-making mechanism. In that case, the mechanism existing in the Russian Federation was fully employed.” To be sure, it seems clear that Putin relied on only a handful of like-minded confidants to make the final decision to invade, but that is not unusual when policymakers are faced with a crisis. All of this is to say that the Russian decision to invade most likely emerged from a deliberative process — one with political allies who shared his core beliefs and concerns about Ukraine.

Moreover, not only was Russia’s decision to invade Ukraine rational, but it was also not anomalous. Many great powers are said to have acted non-rationally when in fact they acted rationally. The list includes Germany in the years before the First World War and during the July Crisis, as well as Japan in the Thirties and during the run-up to Pearl Harbor. In both cases, the key policymakers relied on credible theories of international politics and deliberated among themselves to formulate strategies for dealing with the various issues facing them.

This is not to say that states are always rational. The British decision not to balance against Nazi Germany in 1938 was driven by Prime Minister Neville Chamberlain’s emotional aversion to another European land war coupled with his success at shutting down meaningful deliberation. Meanwhile, the American decision to invade Iraq in 2003 relied on non-credible theories and emerged from a non-deliberative decision-making process. But these cases are the exceptions. Against the increasingly common view among students of international politics that states are often non-rational, we argue that most states are rational most of the time.

This argument has profound implications for both the study and the practice of international politics. Neither can be coherent in a world where non-rationality prevails. Inside the academy, our argument affirms the rational actor assumption, which has long been a fundamental building block for understanding world politics even if it has recently come under assault. If non-rationality is the norm, state behaviour can be neither understood nor predicted, and studying international politics is a futile endeavour. Only if other states are rational actors can practitioners anticipate how friends and enemies are likely to behave in a given situation and thus formulate policies that will advance their own state’s interests.

All of this is to say that Western policymakers would be well-advised not to automatically assume that Russia or any other adversary is non-rational, as they often do. That only serves to undermine their ability to understand how other states think and craft smart policies to deal with them. Given the enormous stakes in the Ukraine war, this cannot be emphasised enough.

This is an edited extract from How States Think: The Rationality of Foreign Policy by John Mearsheimer and Sebastian Rosato