international analysis and commentary

Ukraine-NATO: a post-Vilnius roadmap

from the Aspen Italia's Transatlantic Conference


Kyiv is on its way to NATO’s safe harbor. Port of entry: Washington, July 2024.

The Vilnius NATO summit 2023 was about the defence of Europe. It acknowledged that the main threat to European security is Russia. As in the past with the USSR, that threat can be successfully met by deterrence. But in Vilnius NATO leaders were confronted by more than a threat: by an ongoing war, Russia’s unprovoked war against Ukraine, a NATO partner. Therefore, deterrence had to start by allowing Ukraine to successfully defend itself from it. After Vilnius, deterrence must be enhanced by extending it to Ukraine via NATO membership and turning it from promise to invitation.


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In Vilnius, NATO faced a conundrum. At present. its credibility in guaranteeing European security and deterring Russia hinges on a non-NATO member, Ukraine, and on its capacity to repel the Russian onslaught. NATO’s support is crucial to its successful defence but stops short of the iron-clad insurance of Article 5 of the Washington Treaty. To square the circle, the summit came up with a remarkable Ukrainian package[1] that included:

  • Significant additional military aid: much needed artillery shells from the US, longer-range missiles from France, more tanks from Germany, and F16 pilot training from the Netherlands, Denmark, and other nations.
  • A long-term commitment to support Kyiv’s defence capabilities—equipment, ammunition, production, training, and intelligence—not only for the duration of the war but beyond it, from the major Western military powers.
  • A stable and permanent seat at the NATO table through the new NATO-Ukraine Council, where Kyiv’s ability to shape the agenda, engage in discussions, and ask for specific decisions is comparable to that of all other Allies.
  • The promise to Ukraine of an invitation to join NATO and an assurance that its future is within the Alliance.


The package did not include an actual invitation to join the Alliance – much sought by President Volodymyr Zelensky. It was a misguided, and possibly ill-advised, expectation. An invitation to join NATO in Vilnius was never in the cards, no matter how much Zelenskyy and some Allies pressed for one. So long as war rages, Ukrainian membership in NATO would make all members an active party to the conflict – something that every one of them has sought to avoid since Russia’s full-scale invasion.


Volodymyr Zelensky with Joe Biden


The Vilnius Ukraine package meets three complementary objectives.

First, not to leave Kyiv empty handed, not only about immediate support in the war but also about commitment to its security over the longer term. The latter was further spelled out in the G7 joint framework for providing long-term security guarantees to Ukraine[2].

Second, not to leave uncertainty about Ukraine’s future relationship with NATO.

Third, to cast the relationship as a realistic option. “Membership now” would not have been realistic, not only for the aforementioned reason of avoiding a NATO at war with Russia, but also because “today” would be, at best, “tomorrow” because of national ratifications.

In Vilnius, NATO leaders were able to steer away from past mistakes. On April 3, 2008, the Bucharest summit “agreed that Ukraine and Georgia will become members of NATO”. Fifteen years on the Alliance is still haunted by that undelivered promise. Meanwhile, both countries have suffered invasions and illegal occupations by Russia: Georgia in 2008, Ukraine in 2014 and 2022 – the latter resulting in the ongoing war. Thus, the Bucharest membership promise, still in the books, failed to offer either country any shred of protection.

There are two reasons for it. The formula “will become members of NATO” was actually a compromise papered over a devastatingly divisive debate among Allies (to which this author participated). Those differences were never reconciled – not until the February 24, 2022, game changer. They perpetuated the perception of an Alliance split on Ukraine, even after the first Russian invasion and annexation of Crimea in 2014. Second, the longer the Promised Land membership was not delivered, the more Vladimir Putin felt emboldened to take aggressive actions – 2008, 2014 – with minimal consequences, the more NATO signalled weakness. In parallel, Moscow could build the narrative of being threatened by NATO’s expansion to its borders, irrespective of Ukraine (or Georgia) being nowhere closer to membership after 2008. In fact, the 2014 Maidan crisis and subsequent Russian invasion were triggered by the prospect of Kyiv’s association agreement with the European Union, without NATO being in the picture.

Post-Vilnius must now avoid the post-Bucharest main pitfall of not delivering on its promises. That means that the statement “Ukraine’s future is in NATO” must be followed through. There is little doubt that the ground had already shifted in favor of Ukraine’s NATO membership well before the Vilnius summit. Russia’s behaviour and nationalist rhetoric has made Article 5 the only reliable insurance policy in Europe, witness Finland and Sweden. At present, except for a handful of geographically sheltered free riders, all EU countries are also NATO members. No lesser statesman than Henry Kissinger is now advocating NATO membership for Ukraine[3]. But when will NATO “be in a position to extend an invitation to Ukraine to join the Alliance?” When will “Allies agree, and conditions be met?”


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Ukraine’s NATO membership is no longer in question. That train has left the Vilnius station. Next stop will be the Washington station on July 9-11, 2024, when NATO celebrates its 75th anniversary. The best option is to make it coincide with the final destination. By the Washington summit NATO must be able to extend to Ukraine an invitation to join. Moreover, the invitation can be used both to de-escalate the war and to ensure that Ukraine’s security relies on NATO’s deterrence.

What about the war? Once the Ukrainian counteroffensive has concluded later this year, both Ukraine and Russia will be militarily exhausted. That will create a window of opportunity for opening talks of limited scope – for a temporary ceasefire or even an armistice. At that point, both sides should be amenable to halting or limiting fighting in a localized way and recognise that a resumption of fighting, or its expansion beyond the limited areas along the lines of confrontation, will not serve their interests.

For Kyiv the incentive will be NATO membership. In parallel, NATO’s invitation to Ukraine would make clear to Moscow that its continuation of the war will not prevent Ukraine from joining NATO. To fill the security gap between invitation and actual membership, the United States and other major NATO allies (including at the very least Britain, France, Germany, Italy, and Poland) should accompany the formal invitation to join NATO with bilateral security guarantees, much like they did Finland and Sweden once these nations decided to join NATO last year. These bilateral guarantees would explicitly extend only to those territories controlled and administered by Ukraine, and not to those occupied by Russia.

If the invitation is made contingent on the end of hostilities, Russia will be encouraged to extend the war to lower the chances of Ukraine joining NATO. Neither must happen. NATO needs to make clear in advance that it will proceed with an invitation at the Washington summit nevertheless, and regardless of Moscow’s views. Bringing Ukraine into the Alliance will make deterrence work and de facto put an end to the war.




[1] See NATO communiqué.


[3] Kissinger: for the safety of Europe, get Ukraine into NATO