To take this argument a step further, Putin and other Russian leaders surely understand from the Cold War that occupying counties in the age of nationalism is invariably a prescription for never-ending trouble. The Soviet experience in Afghanistan is a glaring example of this phenomenon, but more relevant for the issue at hand is Moscow’s relations with its allies in eastern Europe. The Soviet Union maintained a huge military presence in that region and was involved in the politics of almost every country located there. Those allies, however, were a frequent thorn in Moscow’s side. The Soviet Union put down a major insurrection in East Germany in 1953, and then invaded Hungary in 1956 and Czechoslovakia in 1968 to keep them in line. There was serious trouble in Poland in 1956, 1970, and again in 1980-1981. Although Polish authorities dealt with these events, they served as a reminder that intervention might be necessary. Albania, Romania, and Yugoslavia routinely caused Moscow trouble, but Soviet leaders tended to tolerate their misbehavior, because their location made them less important for deterring NATO.

What about contemporary Ukraine? It is obvious from Putin’s July 12, 2021, essay that he understood at that time that Ukrainian nationalism is a powerful force and that the civil war in the Donbass, which had been going on since 2014, had done much to poison relations between Russia and Ukraine. He surely knew that Russia’s invasion force would not be welcomed with open arms by Ukrainians, and that it would be a Herculean task for Russia to subjugate Ukraine if it had the necessary forces to conquer the entire country, which it did not.

Finally, it is worth noting that hardly anyone made the argument that Putin had imperial ambitions from the time he took the reins of power in 2000 until the Ukraine crisis first broke out on February 22, 2014. In fact, the Russian leader was an invited guest to the April 2008 NATO summit in Bucharest where the alliance announced that Ukraine and Georgia would eventually become members. Putin’s opposition to that announcement had hardly any effect on Washington because Russia was judged to be too weak to stop further NATO enlargement, just as it had been too weak to stop the 1999 and 2004 waves of expansion.

Relatedly, it is important to note that NATO expansion before February 2014 was not aimed at containing Russia. Given the sad state of Russian military power, Moscow was in no position to pursue revanchist policies in eastern Europe. Tellingly, former U.S. ambassador to Moscow Michael McFaul notes that Putin’s seizure of the Crimea was not planned before the crisis broke out in 2014; it was an impulsive move in response to the coup that overthrew Ukraine’s pro-Russian leader. In short NATO enlargement was not intended to contain a Russian threat but was instead part of a broader policy to spread the liberal international order into eastern Europe and make the entire continent look like western Europe.

It was only when the Ukraine crisis broke out in February 2014 that the United States and its allies suddenly began describing Putin as a dangerous leader with imperial ambitions and Russia as a serious military threat that had to be contained. What caused this shift? This new rhetoric was designed to serve one essential purpose: to enable the West to blame Putin for the outbreak of trouble in Ukraine. And now that the crisis has turned into a full-scale war, it is imperative to make sure he alone is blamed for this disastrous turn of events. This blame game explains why Putin is now widely portrayed as an imperialist here in the West, even though there is hardly any evidence to support that perspective.

Let me now turn to the real cause of the Ukraine crisis.

The Real Cause of the Trouble

The taproot of the crisis is the American-led effort to make Ukraine a Western bulwark on Russia’s borders. That strategy has three prongs: integrating Ukraine into the EU, turning Ukraine into a pro-Western liberal democracy, and most importantly, incorporating Ukraine into NATO. The strategy was set in motion at NATO’s annual summit in Bucharest in April 2008, when the alliance announced that Ukraine and Georgia “will become members.” Russian leaders responded immediately with outrage, making it clear that they saw this decision as an existential threat, and they had no intention of letting either country join NATO. According to a respected Russian journalist, Putin “flew into a rage,” and warned that “if Ukraine joins NATO, it will do so without Crimea and the eastern regions. It will simply fall apart.”

William Burns, who is now the head of the CIA, but was the US ambassador to Moscow at the time of the Bucharest summit, wrote a memo to then-Secretary of State Condoleezza Rice that succinctly describes Russian thinking about this matter. In his words: “Ukrainian entry into NATO is the brightest of all red lines 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.” NATO, he said, “would be seen … as throwing down the strategic gauntlet. Today’s Russia will respond. Russian-Ukrainian relations will go into a deep freeze...It will create fertile soil for Russian meddling in Crimea and eastern Ukraine.”

Burns, of course, was not the only policymaker who understood that bringing Ukraine into NATO was fraught with danger. Indeed, at the Bucharest Summit, both German Chancellor Angela Merkel and French President Nicolas Sarkozy opposed moving forward on NATO membership for Ukraine because they understood it would alarm and anger Russia. Merkel recently explained her opposition: “I was very sure … that Putin is not going to just let that happen. From his perspective, that would be a declaration of war.”

The Bush administration, however, cared little about Moscow’s “brightest of red lines” and pressured the French and German leaders to agree to issuing a public pronouncement declaring that Ukraine and Georgia would eventually join the alliance.

Unsurprisingly, the American-led effort to integrate Georgia into NATO resulted in a war between Georgia and Russia in August 2008—four months after the Bucharest summit. Nevertheless, the United States and its allies continued moving forward with their plans to make Ukraine a Western bastion on Russia’s borders. These efforts eventually sparked a major crisis in February 2014, after a US-supported uprising caused Ukraine’s pro-Russian president Viktor Yanukovych to flee the country. He was replaced by pro-American Prime Minister Arseniy Yatsenyuk. In response, Russia seized Crimea from Ukraine and helped fuel a civil war between pro-Russian separatists and the Ukrainian government in the Donbass region of eastern Ukraine.

One often hears the argument that in the eight years between when the crisis broke out in February 2014 and when the war began in February 2022, the United States and its allies paid little attention to bringing Ukraine into NATO. In effect, the issue had been taken off the table, and thus NATO enlargement could not have been an important cause of the escalating crisis in 2021 and the subsequent outbreak of war earlier this year. This line of argument is false. In fact, the Western response to the events of 2014 was to double down on the existing strategy and draw Ukraine even closer to NATO. The alliance began training the Ukrainian military in 2014, averaging 10,000 trained troops annually over the next eight years. In December 2017, the Trump administration decided to provide Kyiv with “defensive weapons.” Other NATO countries soon got into the act, shipping even more weapons to Ukraine.

Ukraine’s military also began participating in joint military exercises with NATO forces. In July 2021, Kyiv and Washington co-hosted Operation Sea Breeze, a naval exercise in the Black Sea that included navies from 31 countries and was directly aimed at Russia. Two months later in September 2021, the Ukrainian army led Rapid Trident 21, which the U.S. Army described as an “annual exercise designed to enhance interoperability among allied and partner nations, to demonstrate units are poised and ready to respond to any crisis.” NATO’s effort to arm and train Ukraine’s military explains in good part why it has fared so well against Russian forces in the ongoing war. As a headline in The Wall Street Journal put it, “The Secret of Ukraine’s Military Success: Years of NATO Training.”

In addition to NATO’s ongoing efforts to make the Ukrainian military a more formidable fighting force, the politics surrounding Ukraine’s membership in NATO and its integration into the West changed in 2021. There was renewed enthusiasm for pursuing those goals in both Kyiv and Washington. President Zelensky, who had never shown much enthusiasm for bringing Ukraine into NATO and who was elected in March 2019 on a platform that called for working with Russia to settle the ongoing crisis, reversed course in early 2021 and not only embraced NATO expansion but also adopted a hardline approach toward Moscow. He made a series of moves—including shutting down pro-Russian TV stations and charging a close friend of Putin with treason—that were sure to anger Moscow.