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New Atlanticist July 7, 2024

The US and Europe would be safer with Ukraine in NATO. Our war games showed why.

By Matthew Kroenig and Kristjan Prikk

The NATO Summit will take place in Washington, DC, this week, marking the seventy-fifth anniversary of history’s most successful military alliance. A major topic of the summit will be Russia’s war in Ukraine and Ukraine’s future relationship to the Alliance. Some believe that it is risky to talk about Ukraine joining NATO any time soon, but, on the contrary, the free world would be much safer with Ukraine in the Alliance. Membership for Ukraine would be fundamental for lasting peace and stability in the Euro-Atlantic area, benefiting both Ukraine and NATO.

At the 2008 NATO Summit in Bucharest, Romania, NATO members declared that Ukraine would join the Alliance at some unspecified point in the future. At last year’s summit in Vilnius, Lithuania, following Russia’s brutal 2022 invasion of Ukraine, the allies reaffirmed their 2008 commitment, adding the tautological qualifier that they would only “extend an invitation to Ukraine to join the Alliance when Allies agree and conditions are met.”

This year, the Alliance is expected to offer Ukraine a “bridge to membership,” which will consist of a number of measures meant to strengthen Ukraine. These measures are expected to include NATO’s stepped-up role in coordinating military assistance and pledging long-term support, as well as individual Alliance members promising investments in Ukraine’s defense industrial base and further development of bilateral security agreements. However, these steps still fall well short of an invitation to join the Alliance.

Hesitancy to extend an invitation to join the Alliance stems mostly from a concern about what Ukrainian membership would mean for the security of existing NATO allies, including the United States. Would an invitation be provocative to Russia and set off a new cycle of escalation? What does it mean to extend a NATO Article 5 security guarantee to a country already in conflict, and would this be tantamount to a NATO declaration of war against Russia? Even if the current conflict dies down, creating space for Ukraine to join the Alliance, Russian President Vladimir Putin is unlikely to abandon his deep desire to reconquer Ukraine. Would not a future Russian attack on Ukraine set off a direct NATO-Russia war?

Even in scenarios that started with a visible and direct Russian military attack on Ukraine, the conflict quickly de-escalated.

To help answer these questions, the Atlantic Council, in partnership with the Estonian foreign ministry, conducted a series of major tabletop exercises this spring that brought together dozens of leading experts, including current US and allied government officials, to examine future Russia-Ukraine conflict scenarios and their implications for Western security. Some exercises were set in the near future, after Ukraine had already joined NATO, while others gamed out the process of Ukraine joining NATO. The scenarios included variants in which Ukraine had succeeded in taking back all of its territory, and others in which parts of the country remained occupied by Russia.

The results of the exercises were unequivocal: Europe is more stable and secure with Ukraine in NATO. Russia did not choose to escalate when Ukraine was offered NATO membership, and in all scenarios, Russia was much more cautious in its interactions with Ukraine once it was a member of NATO. Even in scenarios that started with a visible and direct Russian military attack on Ukraine, the conflict quickly de-escalated. Both sides had strong incentives to avoid a direct NATO-Russia conflict—one that could result in nuclear war.

This finding corresponds with Russia’s behavior over the past decade and a half. Putin has been willing to use force against countries outside of NATO, including Georgia and Ukraine, but he has been deterred from attacking NATO countries.

Moreover, at present, some observers assume that only the West has an overriding incentive to avoid nuclear escalation in Ukraine. But with Ukraine in NATO, which is a nuclear-armed alliance, Putin would also have to fear the possibility of nuclear conflict, making him much more cautious in his relations with Ukraine.

The lesson coming out of these exercises is clear. This week, Western powers can offer Ukraine a bridge to NATO, but for the sake of a better future for the entire Alliance, the bridge must be short, it must be made of steel, and it should end with a firm invitation for Ukraine to join NATO.


Matthew Kroenig is vice president and senior director of the Atlantic Council’s Scowcroft Center for Strategy and Security.

Kristjan Prikk is Estonia’s ambassador to the United States.

Further reading

Related Experts: Matthew Kroenig

Image: Handout photo shows NATO Secretary General Jens Stoltenberg with Ukraine President Volodymyr Zelensky speak to the press at the start of the meetings of NATO Ministers of Defence on October 11, 2023 in Brussels, Belgium. Photo by Nato via ABACAPRESS.COM