Admitting Ukraine to Nato would be a mistake for both Ukraine and Nato

Ukraine and its supporters are pushing the White House for a stronger pledge to bring the country into Nato at the 75th anniversary July summit in Washington. Their push is understandable – but this is a dangerous idea that would commit the US to a long-term defense of Ukraine, while creating a major vulnerability for Nato, which would end up weaker, not stronger, than today. Nato membership is also not the best option for Ukraine.

Joe Biden has already gone to lengths to show Ukraine support by signing a bilateral security agreement in Italy last week, not to mention prying $175bn in US assistance from Congress. He should use the upcoming summit to put Ukraine’s Nato membership on to the back burner.

A pledge to give Ukraine membership in Nato would risk the credibility of the alliance’s existing mutual defense commitment as enshrined in Article 5 of the North Atlantic Treaty. That pledge commits members of the alliance to view an attack on one of them as an attack on all. But applying this standard to Ukraine after the war would be extremely difficult, and even more difficult while it is going on.

Remarkably, given the stakes and pressure to bring Ukraine into the alliance, there has been no serious military analysis of what the military requirements for a Nato defense commitment to Ukraine would be. Even a cursory analysis, however, suggests they will be very heavy.

Under almost any imaginable end to the war, Ukraine will face hostility from Russia, which will remain far more militarily capable than Ukraine. Currently Ukraine has over 300,000 men under arms. That army will need to be demobilized once the war is over if there is to be any hope of restarting the Ukrainian economy.

This means that if Ukraine were to join Nato, other members of the alliance would need to deploy their own forces, probably in significant numbers, directly into Ukraine on an indefinite basis. In the past, such frontline deployments – for example in the Baltic states and Poland – have relied heavily on US troops, which are widely considered the most effective deterrent against Russia. But the US is very unlikely to deploy forces and other resources on the scale needed to defend Ukraine.

Not only is the center of gravity of US interests shifting to Asia, but American public support for Ukraine has been declining in both political parties, according to recent polling by organizations such as Pew. The prospect that a future US president – Republican or Democrat – would be willing to send US troops into Ukraine and thereby risk a direct confrontation with Russia is small. Even the president, who instinctively supports Ukraine, has been unwilling to send in US forces, thanks to well-placed concerns of an escalating war.

True, the shock of the war has led many European capitals to increase their commitments to spend more on defense, but it will take years for US allies in Europe to rebuild their military might. Some advocates for Ukraine’s membership in the alliance may hope that nuclear weapons will fill the gap, but the idea that Nato would be willing to fight a nuclear war with Russia in order to protect Ukraine, potentially ending civilization as we know it, is a fantasy.

A Nato commitment to defend Ukraine as an ally could therefore end up worth little more than the paper it was written on. This would draw into question existing commitments to other allies, weakening the alliance and other US global commitments.

Moreover, even declaring a serious intention to bring Ukraine into Nato would complicate any efforts to negotiate an end to the fighting, because Russia is so neuralgic about the issue. Anyone who recognizes that this war will have to end in negotiations – including the Biden administration itself – should not therefore make a pledge to bring Ukraine into Nato at this point in time. Gestures toward Nato membership would also play into Putin’s narrative for the war, which he has justified in part on the grounds that he is fighting an aggressive, expansionist Nato.

A firmer pledge to bring Ukraine into Nato at the July summit would also undermine the leverage the alliance has to bring about the political and economic reforms that Ukraine will badly need once the war is over. In past rounds of Nato enlargement, the possibility, but not the guarantee, of Nato membership has served as a powerful tool to encourage democratic and economic reforms in aspirant members. To give that leverage up now would be a huge mistake, and create pressure to adjust alliance standards downward should Ukraine’s postwar reform efforts falter.

Ukraine does need some arrangement for its future security, but there are better options. The west has a clear interest in supporting Ukraine with help ending the war on favorable terms, with weapons to protect its civilian population and avert a catastrophic rout, and with reconstruction. Proposals to extend existing arrangements in some form beyond the end of the war are sensible and will be necessary not only to provide Ukraine with security once the war is over, but to convince Ukraine to accept what is sure to be a painful armistice when that time comes.

Nato has already pledged hundreds of billions to Ukraine, an extraordinarily generous sum. Ukraine’s leaders should stop asking for Nato membership and the Biden administration should stop considering it. The focus of the summit should instead be on ending the war and getting Ukraine started down the road to recovery. This is the only way that Ukraine can flourish and thereby truly win this war.

Christopher S Chivvis is a senior fellow at the Carnegie Endowment for International Peace, where he directs the program on American Statecraft. He served as the US national intelligence officer for Europe from 2018 to 2021.