Don’t Let Ukraine Join NATO

The stakes could not be higher. Membership in NATO encompasses a commitment by the allies to fight and die for one another. Partly for this very reason, its members worked throughout the post–Cold War era to avoid expanding the alliance to states that faced a near-term risk of being attacked. NATO leaders have also long understood that admitting Ukraine involves a very real possibility of war (including nuclear war) with Russia. Indeed, the chance of such a conflict and its devastating consequences is the main reason that the United States and other NATO members have sought to avoid being drawn in more deeply into the war in Ukraine. The tension is clear: almost no one thinks that NATO should fight directly with Russia for Ukraine today, but many favor promising Ukraine a path into the alliance and committing to fight for it in the future.

Ukraine should not be welcomed into NATO, and this is something U.S. President Joe Biden should make clear. Kyiv’s resistance to Russian aggression has been heroic, but ultimately states do what is in their self-interest. And here, the security benefits to the United States of Ukrainian accession pale in comparison with the risks of bringing it into the alliance. Admitting Ukraine to NATO would raise the prospect of a grim choice between a war with Russia and the devastating consequences involved or backing down and devaluing NATO’s security guarantee across the entire alliance. At the Vilnius summit and beyond, NATO leaders would be wise to acknowledge these facts and close the door to Ukraine.

Too Close for Comfort

At the NATO summit in Romania in 2008, U.S. President George W. Bush took everyone by surprise by lobbying for Georgia and Ukraine to join the alliance. It was Bush’s last NATO summit as president, and he wanted to “lay down a marker” for his legacy, according to an administration official at the time. A number of European member states, including Germany and France, balked at the idea out of concern over the inevitable Russian reaction and the implications for the alliance. The diplomatic deadlock yielded a compromise in which NATO declared that the countries would become members someday but provided no plan for getting them there. Yet even this compromise brought a forceful denunciation from Russian President Vladimir Putin. Speaking in Bucharest, Putin said:

Four months later, Russia invaded Georgia and still occupies some of its territory to this day. In 2014, Russia annexed Crimea in a prelude to the full-scale war against Ukraine in February 2022. Russia’s behavior is thuggish, illegitimate, and dangerous. Nevertheless, it underscores the core issue at play: even as NATO remains formally committed to Ukrainian (and Georgian) accession, further NATO enlargement into areas that Moscow views as uniquely central to its national security means courting war with Russia.

Right Ends, Wrong Means

To date, advocates of further U.S. and NATO involvement in the Ukraine war have failed to clarify the U.S. strategic interests at stake. The Biden administration has argued that history shows that “when dictators do not pay the price for their aggression, they cause more chaos and engage in more aggression,” as the president himself put it. But Russia has already paid an enormous price for its aggression. By holding its ground and pushing back the Russian military, Ukraine has humiliated Putin, who just two years ago denigrated Ukraine as a non-country. It will take decades for Russia to rebuild its military even to the shabby state it was apparently in when Putin launched the war; the United States estimates that more than 100,000 Russian fighters have been killed or injured. The recent mutiny launched by the mercenary chief Yevgeny Prigozhin suggests that the war may destabilize Putin’s rule at home.

The U.S. interest in admitting Ukraine to NATO is even less clear, with a tangle of arguments present in the policy discourse. One view holds that European stability and security require Kyiv to join the alliance. By this logic, if Putin is not stopped in Ukraine, he will expand his aims and attack NATO member states. A second line of reasoning focuses on Ukraine itself, arguing that NATO membership is the only way to protect the country from Russian designs. Finally, there is a sense that Ukraine has “earned” NATO membership by fighting and weakening an adversary of the alliance. In this view, deepening NATO cooperation with Ukraine would reward its heroism and add another layer of deterrence against a renewed Russian assault.

These claims are understandable but wrong. For one thing, Ukraine’s resistance to Russian bellicosity is noble, but noble actions and even effective self-defense do not themselves justify taking on the high risks of an open-ended security commitment. More important, the stakes of the game today do not warrant Ukraine’s accession to NATO.

For over 100 years, U.S. aims in Europe have been counterhegemonic: in World War I, World War II, and again in the Cold War, the United States bore high costs to prevent one country from dominating the continent. Today, however, even a Russia that somehow defeated Kyiv would not be poised to control Europe. Had Russia annexed all of Ukraine without firing a shot, its GDP would have grown by 10 percent, making it barely larger than Italy’s. True, Russia would have also won itself a second major port on the Black Sea, but it would still remain far weaker than the European members of NATO. As even Robert Kagan has acknowledged, “There is no way that Putin’s conquest of Ukraine” would have “any immediate or even distant effect on American security.”

Thankfully, though, Russia is not going to conquer Ukraine. Its military campaign has been an embarrassment, with the war proving Russia’s army to be less than a pale shadow of the Soviet one. The idea that Russia could pose a serious threat to Poland, much less to France or Germany, is outlandish. Couple this with the U.S. nuclear arsenal and the Atlantic Ocean, and one can see that the gains for Washington in inviting Ukraine to join NATO are limited.

Even if Ukraine is, as its foreign minister, Dmytro Kuleba, argued in Foreign Affairs, “defending NATO’s entire eastern flank and sharing what it learns with alliance members,” it is unclear why it must join the alliance for the United States to reap these benefits. Unless it were to surrender to Russian domination—which Kyiv has demonstrated it is not inclined to do—Ukraine’s geography consigns it to acting as a bulwark against Russia irrespective of NATO membership. The events since February 2022 show that Ukraine does not need to be in NATO for the United States and its allies to effectively help it resist Russian aggression.

Unkept Promises

Admitting Ukraine to NATO would also present problems for the alliance, especially the security guarantees embedded in Article 5 of the alliance’s founding treaty. To be sure, Article 5 only formally commits the NATO allies to treat an attack on one as an attack on all and to render the assistance they “deem necessary.” In practice, however, member states have viewed NATO membership and the Article 5 guarantees that go along with it as a U.S. commitment to go to war on behalf of its allies. As President Barack Obama declared on a visit to Estonia in 2013,

Or as Biden described the commitment more recently, Article 5 constitutes “a sacred oath to defend every inch of NATO territory.” This is why Ukraine believes NATO membership will help protect it against future Russian aggression.

The problem with extending such guarantees to Ukraine is twofold. First, an Article 5 guarantee could pull the United States into a direct conflict with Russia. Unlike other countries that recently joined the alliance, Ukraine will likely continue to have an unresolved dispute with Russia inside its borders. Not only will Moscow and Kyiv have rival claims on territory, but the surge of Russian and Ukrainian nationalism provoked by the war will limit room for diplomacy. Under these conditions, it is not difficult to imagine how relations could further deteriorate even if an arrangement is reached to end the fighting. If Ukraine were in NATO, the United States could be pushed to come to Ukraine’s defense by deploying troops and even threatening to use nuclear weapons on Ukraine’s behalf. American policymakers may hope to deter future Russian aggression against Ukraine by creating a path for Kyiv into NATO, but doing so creates a real possibility of drawing the United States into what Biden has called a “World War III” scenario.

Extending Article 5 protections to Ukraine could also undermine their overall credibility. For the past 16 months, the Biden administration has made it clear that it does not believe it is worth directly fighting Russia in a dispute over Ukraine. Many influential Republican politicians—including the GOP presidential frontrunner, former President Donald Trump—are particularly disinclined to risk American lives for Ukraine. On the other hand, Russian policymakers from Putin down have revealed that they do feel Ukraine is worth fighting for, even at great cost.

Under these circumstances, an American commitment to fight for Ukraine would be open to question. Russia might well test that pledge, leading to future crises. If called on to fight, it is plausible that the United States could renege on its assurances, leaving Ukraine in the lurch. And should the United States back away from Ukraine when it is under attack, other vulnerable NATO allies such as the Baltic states would naturally question the strength of the alliance’s security commitments backed by American military power. A true credibility crisis for NATO could result.

Some advocates for Ukraine’s joining NATO argue that the sort of weapons, training, and diplomatic support already being given to Kyiv are sufficient to meet NATO’s Article 5 mandate, meaning it is not necessary to also promise or deploy military forces. Yet if Article 5 allows the United States and other allies to stop short of going to war to protect a member, it turns NATO into a tiered alliance, with some members (such as France and Germany) remaining confident that Washington would use force to come to their aid, and others far from certain. That could prompt an intra-alliance scramble as members struggle to determine which kind of Article 5 guarantee they enjoy. Moreover, offering this more limited Article 5 guarantee is of uncertain help to Ukraine. After all, since Ukraine is already receiving many of the other benefits of NATO membership, it can only be the prospect of direct intervention by the United States and others via Article 5 that adds deterrent and political value to Kyiv.

Paying For It

There is also the question of the costs of defending Ukraine. NATO is already struggling to find the conventional forces and operating concepts it needs to service the alliance’s existing commitments. The war in Ukraine has made clear that modern, high-intensity conflict between conventional militaries consumes incredible quantities of resources. Viewed in this light, inviting Ukraine to join NATO would exacerbate the gap between the alliance’s commitments and its capabilities.

Of course, since the NATO countries as a whole are wealthier, more technologically advanced, and more populous than Russia, that gap could theoretically be filled with an aggressive rearmament program. European members of NATO, however, have a long way to go because they have underinvested in conventional military power since the Cold War. Ukraine itself is a partial exception to this general trend, but even here, Ukraine’s admirable military performance is—as Zelensky, other Ukrainian leaders, and outside analysts have acknowledged—due in large part to the exceptional scope and scale of military aid provided by the United States and its partners. Should Ukraine join the alliance, the burden of finding the resources to defend Ukraine short of nuclear war is therefore likely to fall disproportionately on the United States.

At a time when Washington already faces serious resource demands both at home and in Asia, it risks being backed into a corner: with Ukraine in NATO, Washington will need to divert resources from other priorities, some of which are arguably of greater importance, or accept increased risk along what would be a dramatically expanded eastern front. In either case, the United States will have incurred large costs and burdens at a moment when American time, attention, and resources are needed elsewhere.

Finally, these costs could balloon because of the perverse incentives that offering Ukraine a path into NATO creates for Moscow. Russia has shown itself willing to fight over the future strategic orientation of Ukraine, but the United States and others have not. Moscow knows this. Tragically, offering Ukraine a path into NATO is therefore likely to give Russia reason to continue its war against Ukraine for as long as possible in order to avoid creating conditions in which Ukraine can start on the road to NATO membership. In this sense, an invitation to join the alliance promises to prolong the current bloodshed and make any diplomatic settlement less likely. On the other hand, if the current war were to abate and Ukraine began the accession process, Moscow would be encouraged to lash out again in a bid to prevent that move before the process was complete. Unless NATO could admit Ukraine via some kind of fait accompli—no easy task given the alliance’s requirements for unanimity and consensus—a plan for long-term membership makes Russian aggression in Ukraine more rather than less likely. In either case, the costs of defending Ukraine go up.

Ukraine’s desire to join NATO is understandable. It makes perfect sense that a country that has been bullied and invaded by a stronger neighbor would seek the protection of an outside power. Still, strategy is about choice, and the United States’ choices today are stark. For much of the post–Cold War period, the United States could expand its international commitments at relatively low cost and risk. Those circumstances no longer exist. With fiscal pressures at home, a grave challenge to its position in Asia, and the prospect of escalation and an erosion of credibility vis-à-vis Moscow, keeping Ukraine out of NATO simply reflects U.S. interests. Instead of making a questionable promise that poses great dangers but would yield little in return, the United States should accept that it is high time to close NATO’s door to Ukraine.