Op-ed: Why admitting Ukraine into NATO would be a risky mistake

NATO enlargement has stretched the alliance thin. Adding Ukraine would make the problem worse.
Outgoing NATO Secretary General Jens Stoltenberg with Ukrainian President Volodymyr Zelenskyy.

By Stephen Wertheim

Stephen Wertheim is a senior fellow in the American Statecraft Program at Carnegie Endowment for International Peace. He is the author of "Tomorrow, the World: The Birth of US Global Supremacy."

18 Aug 2024

This op-ed is the con-argument for admitting Ukraine into NATO. Read the pro-side here.

In the decade since “America First” took over one of the two major political parties in the United States, transatlanticists on both sides of the ocean have reacted with a sense of dismay, denial and — above all — disorientation. But turmoil within NATO should not have come as a shock, even if its most immediate catalyst, Donald Trump, cut an unlikely figure. 

As NATO was searching for a new purpose after the Cold War, its staunchest advocates, especially in Washington, set up the alliance for the crisis it is experiencing now. In the 1990s, they devised a tactically brilliant method for enlarging NATO, one that frontloaded the benefits and backloaded the costs. Their short-term success leaves it to today’s generation to figure out how an expanded, lopsided and hollowed-out alliance should make good on its commitment to common defence.

Admitting Ukraine would seriously exacerbate that challenge. 

When the administration of US President Bill Clinton initially sought to expand NATO, it faced daunting obstacles. Cold War divisions were supposed to be healing, but Russia opposed the enlargement of a military alliance that was historically aimed at Moscow. The American public craved a “peace dividend,” but a bigger NATO would create additional defence commitments that made Pentagon leaders balk. 

The lure, and trap, of enlargement creep

If the alliance was going to expand, moreover, many central and eastern European governments were looking for a way in. The last thing they wanted was to get stuck on the wrong side of Europe’s new dividing line. Yet the more states that tried to join, the more daunting the accession process would become. The US Senate needed a two-thirds majority to approve each new member, and every existing NATO ally had to agree. 

The White House figured out a clever solution, summarized internally as "small is beautiful" plus "robust open door." NATO would admit only a few states at first while making clear that many more would receive serious consideration in the not-too-distant future. 

The first countries — the Czech Republic, Hungary and Poland — made a uniquely attractive trio. They had well-known democratic aspirations and vocal diasporic communities in politically important US states. Located in central Europe, they were more militarily defensible than potential candidates further to the east, and their admission was less offensive to Russia. 

The plan worked. In 1998, the Senate voted to admit the three countries by a comfortable margin of 80–to–19. Just as US officials hoped, expanding NATO once in the post-Cold War era made it easy to do so again — and again. In the “big bang” of 2004, the alliance added seven more members, including the three small Baltic states that bordered Russia and had been Soviet republics. The Senate approved unanimously. 

During the chamber’s cursory debate, the possibility that American troops might one day have to fight Russia to protect these countries was an afterthought. In the wake of the 9/11 attacks, senators were less interested in building a viable European security architecture than in symbolically rewarding the newcomers for supporting America’s latest wars in Afghanistan and especially Iraq. 

Too big (not) to fail? 

All told, since NATO’s original Soviet adversary collapsed in 1991, the alliance has doubled in size — from 16 to 32 members. 

However one judges the merits of enlargement itself, it was an error to make commitments first and consider the costs later. Only now — for the first time since the Cold War — is the American political system beginning to have a real conversation about what the US is prepared to do to defend Europe. Russian aggression against Ukraine in 2014 and 2022 has forced the issue, turning a theoretical concern into an acute policy problem. 

Still, one cannot say with confidence that any president would order troops into combat to repel, say, a Russian invasion of Latvia; or that Congress would declare war and authorize funds to wage it; or that American society would sustain support for such a conflict once initiated. 

Already stretched thin, NATO is considering bringing in Ukraine after the current war. The debate over this prospect reflects the damaging legacy of the past three decades, in which NATO forgot how to take deterrence and defence — ostensibly its core mission — seriously. 

For many proponents of Ukrainian membership, the mere act of admitting the country would suffice to deter Russia from invading ever again. That is wishful thinking. Since Russia began seizing Ukrainian land in 2014, NATO members have declined to intervene militarily. Their inaction demonstrates that they do not believe the stakes of conflict in Ukraine, while significant, justify the price of war. 

US President Joe Biden has vowed: “We will not fight a war against Russia in Ukraine. Direct confrontation between NATO and Russia is World War Three, something we must strive to prevent.” 

If that remains the case, NATO should not admit Ukraine, which would then receive the protection of Article 5. If Russia dared to test that with another assault, the alliance would be confronted with a perilous choice: war with Russia or the unravelling of NATO’s security guarantee as Article 5 becomes a dead letter.  

Russian leaders wouldn’t be crazy to doubt NATO’s willingness to do for Ukraine what it didn’t do for it in 2014 or 2022. Invading again would be a big risk, of course, but could also bring an enormous reward: shattering NATO itself. 

Back to alliance basics

Rather than make promises to Ukraine that it cannot or will not keep, the transatlantic alliance should prepare to defend its existing members. It has much work to do. Over the next decade, European countries should become capable of, and responsible for, defending Europe, regardless of who takes the White House in November. 

Indeed, from a European perspective, the US election may be less important for who wins than for what it has already revealed. Clearly both political parties regard China as the main rival to the US and Asia as the most important region. American politics is starting to price in the true costs of overseas commitments without delivering a solution that would allow European allies to rest easy. Their security is far from the minds of American voters, who could well return Trump to the Oval Office. 

Trump is capable of just about anything, from escalating the war in Ukraine to leaving NATO altogether. He deserves credit for catalysing an overdue debate, but the prescription he keeps coming back to — bullying allies into paying more for defence — evades the central problem that European spending won’t fix: American overcommitment. What’s needed is a responsible transition to European leadership of European defence, with the US moving to a supporting role within NATO. 

As for Democrats, Vice President Kamala Harris, if elected, will not inherit a viable formula from her predecessor. Biden touts NATO as a “sacred obligation,” but theological declamations cannot expunge strategic dilemmas. His administration took office seeking to inject discipline into US foreign policy. It leaves entangled in wars in Europe and the Middle East while trying to prioritize China. 

If NATO is to live up to its present and future responsibilities, it must be clear-eyed about its past mistakes. Admitting Ukraine anytime soon would double down on them instead, just when the times demand creative thinking and seriousness of purpose.