The Kremlin objected to NATO enlargement from the get-go. As early as 1993, Russian president Boris Yeltsin warned that Russians across the political spectrum “would no doubt perceive this as a sort of neo-isolation of our country in diametric opposition to its natural admission into Euro-Atlantic space.” In a face-to-face meeting with President Clinton in 1995, Yeltsin was more direct: 

I see nothing but humiliation for Russia if you proceed … Why do you want to do this? We need a new structure for Pan-European security, not old ones! ... For me to agree to the borders of NATO expanding towards those of Russia – that would constitute a betrayal on my part of the Russian people.

Moscow’s discomfort only grew when Putin took the helm in 1999 and reversed Yeltsin’s flirtation with a more liberal brand of governance. At the Munich Security Conference in 2007, Putin declared that NATO enlargement “represents a serious provocation” and asked, “Why is it necessary to put military infrastructure on our borders during this expansion?”

Russia soon began concrete efforts to stop further enlargement. In 2008, not long after NATO pledged that Georgia and Ukraine “will become members of NATO,” Russia intervened in Georgia. In 2012, Moscow allegedly attempted to organize a coup in Montenegro to block its accession to the alliance, and later worked to prevent North Macedonia’s membership. These efforts in the Balkans were to no avail; Montenegro joined the alliance in 2017 and North Macedonia followed suit in 2020. Now Putin has invaded Ukraine, in part to block its pathway to NATO. In his February 24 address to the nation justifying the beginning of the “special military operation,” Putin pointed to “the fundamental threats which irresponsible Western politicians created for Russia ... I am referring to the eastward expansion of NATO, which is moving its military infrastructure ever closer to the Russian border.”

The United States has largely dismissed Russia’s objections. While the Kremlin has been anxiously watching NATO’s advance, Washington has viewed NATO’s eastward expansion primarily through the benign lens of America’s exceptionalist calling. Enlarging the alliance has been about spreading American values and removing geopolitical dividing lines rather than drawing new ones.

As he launched NATO’s open-door policy, President Clinton claimed that doing so would “erase the artificial line in Europe drawn by Stalin at the end of World War II.” Madeleine Albright, his secretary of state, affirmed that “NATO is a defensive alliance that ... does not regard any state as its adversary.” The purpose of expanding the alliance, she explained, was to build a Europe “whole and free,” noting that “NATO poses no danger to Russia.” That’s the line that Washington has taken ever since, including when it came to Ukraine’s potential membership. As the crisis over Ukraine mounted, President Joe Biden insisted that, “the United States and NATO are not a threat to Russia. Ukraine is not threatening Russia.” Secretary of State Antony Blinken agreed: “NATO itself is a defensive alliance ... And the idea that Ukraine represents a threat to Russia or, for that matter, that NATO represents a threat to Russia is profoundly wrong and misguided.” America’s allies have mostly been on the same page. Jens Stoltenberg, NATO’s secretary-general, affirmed during the run-up to Russia’s invasion that: “NATO is not a threat to Russia.”

Yet Russia saw things quite differently—and not without reason. Geography and geopolitics matter; major powers, regardless of their ideological bent, don’t like it when other major powers stray into their neighborhoods. Russia has understandable and legitimate security concerns about NATO setting up shop on the other side of its 1,000-mile-plus border with Ukraine. NATO may be a defensive alliance, but it brings to bear aggregate military power that Russia understandably does not want parked near its territory.

Indeed, Moscow’s protests have been, ironically, very much in line with America’s own statecraft, which has long sought to keep other major powers away from its own borders. The United States spent much of the nineteenth century ushering Britain, France, Russia, and Spain out of the Western Hemisphere. Thereafter, Washington regularly turned to military intervention to hold sway in the Americas. The exercise of hemispheric hegemony continued during the Cold War, with the United States determined to box the Soviet Union and its ideological sympathizers out of Latin America. When Moscow deployed missiles to Cuba in 1962, the United States issued an ultimatum that brought the superpowers to the brink of war. After Russia recently hinted that it might again deploy its military to Latin America, the State Department spokesperson Ned Price responded: “If we do see any movement in that direction, we will respond swiftly and decisively.” Given its own track record, Washington should have given greater credence to Moscow’s objections to bringing Ukraine into NATO.

For almost three decades, NATO and Russia have been talking past each other. As Russian foreign minister Sergey Lavrov quipped amid the flurry of diplomacy that preceded the Russian invasion, “we’re having the conversation of a mute person with a deaf person. It’s as though we are hearing each other, but not listening.”

Russia’s invasion of Ukraine makes clear that this disconnect between Russia and the West has exploded into the open, finally doing so for a number of reasons. Moscow took the entry into NATO of a band of countries stretching from the Baltics to the Balkans as a strategic setback and political insult. Ukraine, in particular, looms much larger in the Russian imagination; in Putin’s own words, “Russians and Ukrainians are one people. Kiev is the mother of Russian cities.” The 2019 split of the Orthodox church of Ukrainian from its Russian counterpart was an especially bitter pill; the Ukrainian church had been subordinated to the Moscow patriarch since 1686. Russia today is far more capable of pushing back than it was during the early post-Cold War era, bolstered by its economic and military rebound and its tight partnership with China.

Yet the Kremlin made several gross miscalculations in proceeding with its invasion of Ukraine. It vastly underestimated the willingness and capability of Ukrainians to fight back, producing early Russian setbacks on the battlefield. Moscow saw numerous sources of Western weakness—Brexit, the chaotic withdrawal from Afghanistan, the COVID-19 pandemic, inflation, ongoing polarization, and populism—leading to an underestimation of the strength and scope of the West’s response. In Putin’s mind, a combination of Russian strength and Western frailty made it an opportune moment to throw down the gauntlet in Ukraine. But Putin was wrong; the West has demonstrated remarkable steadiness as it has armed Ukraine and imposed severe sanctions against Russia.

These miscalculations help shed light on why Putin chose to address his grievances through war rather than diplomacy. Indeed, Putin had the opportunity to settle his objections to Ukraine’s membership in NATO at the negotiating table. Last year, President Biden acknowledged that whether Ukraine joins the alliance “remains to be seen.” Amid the flurry of diplomacy that preceded the Russian invasion, President Emmanuel Macron of France floated the idea of “Finlandization” for Ukraine—effective neutrality—and proposals for a formal moratorium on further enlargement circulated. Ukrainian president Volodymyr Zelenskyy admitted that the prospect of Ukraine joining NATO may be “like a dream.” His ambassador to the United Kingdom indicated that Kyiv wanted to be “flexible in trying to find the best way out,” and that one option would be to drop its bid for NATO membership. The Kremlin could have picked up these leads, but instead opted for war.

THE SAGA of NATO enlargement exposes the gap between the West’s ideological aspirations and geopolitical realities that has been widening since the 1990s. During the heady decade after the end of the Cold War, the United States and its allies were confident that the triumph of their power and purpose cleared the way for the spread of democracy—an objective that the enlargement of NATO would presumably help secure.

But from early on, the Western foreign policy establishment allowed principle to obscure the geopolitical downsides of NATO enlargement. Yes, NATO membership should be open to all countries that qualify, and all nations should be able to exercise their sovereign right to choose their alignments as they see fit. And, yes, Moscow’s decision to invade Ukraine was in part informed by fantasies of restoring the geopolitical heft of the Soviet days, Putin’s paranoia about a “color revolution” arising in Russia, and his delusions about unbreakable civilizational links between Russia and Ukraine.

Yet the West erred in continuing to dismiss Russia’s objections to NATO’s ongoing enlargement. In the meantime, NATO’s open door policy encouraged countries in Eastern Europe to lean too far over their strategic skis. While the allure of joining the alliance has encouraged aspirants to carry out the democratic reforms needed to qualify for entry, the open door has also prompted prospective members to engage in excessively risky behavior. In 2008, soon after NATO ignored Russian objections and promised eventual membership to Georgia and Ukraine, Georgia’s president, Mikheil Saakashvili, launched an offensive against pro-Russian separatists in South Ossetia with whom the country had been sporadically fighting for years. Russia responded promptly by grabbing control of two chunks of Georgia—South Ossetia and Abkhazia. Saakashvili thought the West had his back, but he miscalculated and overreached.