In this series from the American Statecraft Program, James Goldgeier and Joshua Shifrinson discuss and debate the issues surrounding NATO enlargement in a twenty-first-century exchange of letters. Read the previous entry here.

Dear Josh,

Alas, I think you have it exactly backward. NATO enlargement isn’t the cause of Russian President Vladimir Putin’s full-scale war against Ukraine. But Putin’s aggression is the primary cause of NATO taking Ukrainian membership more seriously, and it led Finland and Sweden to do something that was (highly) unlikely until February 2022: to seek to join the alliance.

Concordia College professor Rebecca R. Moore’s chapter on the evolution of the NATO-Ukraine relationship in our NATO enlargement book is particularly telling. “Over the past three decades,” she writes, “NATO has repeatedly affirmed that its door remains open. In reality, it has been tiptoeing around Russia since the early 1990s, especially on the question of Ukraine’s membership in NATO.” Perhaps most importantly, she notes, “The principal problem with the argument that NATO enlargement precipitated Russian aggression is not only that it mischaracterizes the impetus for NATO enlargement; it also presumes that in its absence, Russian foreign policy would have steered a different course.”

Her last point is a key difference underlying our disparate views of the wisdom of NATO enlargement. You and I agree that NATO enlargement provided for greater security and stability across Central and Eastern Europe while at the same time contributing to the deterioration in U.S.-Russia relations. I’ve supported the NATO enlargement policy over the years (except for the 2008 Bucharest Summit Declaration regarding Ukrainian and Georgian membership, as I noted in my previous letter) because I don’t believe that in its absence U.S.-Russia relations would have looked all that different. Thus, enlargement’s benefits for Central and Eastern European stability and security loom large in my thinking. As we have discussed often, you do believe a different relationship between the United States and Russia might have emerged if NATO had not enlarged, so you are much more skeptical of the policy.

One of the key arguments in your recent letter is that “explaining change with a constant is difficult,” so Russian imperialism cannot be the primary cause of Moscow’s aggression, as I argued in my initial letter. It’s interesting that you make that point, since arguments against blaming NATO enlargement for Russian aggression also suggest that we can’t explain change with a constant. Russia experts Robert Person and Michael McFaul argue, for example, that tensions between Russia and the West have varied during a period of continual NATO enlargement, and they instead argue a rise in tensions correlates more with “waves of democratic expansion in Eurasia.”

Ultimately, your argument is perhaps not that dissimilar: “By 2021, Moscow probably perceived that its window of opportunity to arrest Ukraine’s Westward drift was closing.” As Person and McFaul suggest, that could well be simply about democratic trends, not about NATO enlargement.

It also may be the case that Putin launched his full-scale invasion because he thought the opportunity was ripe. After all, U.S. President Joe Biden’s administration came into office in 2021 making clear its focus was on the China challenge. That was the reason Biden was promoting a “stable and predictable” relationship with Russia, something that was destined to be difficult to achieve. Ukraine joining NATO was nowhere in sight. But Putin may have believed it was time to move to incorporate more, if not all, of Ukrainian territory in order to realize his vision of Russian greatness. He apparently thought it was a moment when he might actually get away with it.

Biden is clearly reluctant to move forward with NATO membership for Ukraine. He would have been even more reluctant absent the full-scale Russian invasion, given his original goal of stable and predictable relations with Moscow. The only reason Ukrainian membership is now actually on the table for serious discussion, and the only reason Finland and Sweden sought membership, is due to Russia’s February 2022 invasion. Putin’s latest aggression is causing the current wave of NATO enlargement, not the reverse.

You asked me how I “rate both the ease and feasibility of deterring Russia” if Ukraine joins NATO upon an end to the war. As I noted in my earlier letter, I have come to the conclusion that only NATO’s Article 5 guarantee can deter Russian aggression against Ukraine over the long term. Absent alliance membership for Ukraine, a Russian assault will always be a distinct possibility. The idea that the West can deter Russian aggression simply by providing Ukraine with the weapons it needs to defend itself, as the United States does for Israel, seems highly unlikely to me, given Moscow’s continued designs on Ukrainian territory. Ukraine has shown an extraordinary capacity to defend itself with Western assistance, but that does not seem yet to be a sufficient deterrent.

I don’t think it’s easy, but it’s certainly feasible, to deter Russian aggression against any NATO member, given the Russian fear of a war with NATO. It’s even easier if Europe boosts its investments in defense, as the recent NATO summit communiqué suggested it aspires to do. We’ll see. You and I agree that Europe has yet to do enough to lessen its extreme dependence on the United States for its security. The NATO summit rhetoric on defense planning and production was a good step, but the alliance has to translate rhetoric into greater action by European countries that have historically underinvested in defense.

Sincerely,

Jim

Read more from Debating NATO Enlargement:

• Letter 1: Why NATO Should Accept Ukraine
• Letter 2: NATO Must Be Cautious
• Letter 4: The Crucial Question
• Letter 5: What Deters Russian Aggression
• Letter 6: What Washington Got Wrong in the 1990s
• Letter 7: No Choice but Containment