The fact that Sweden applied for NATO membership is itself an indication of how much European security has deteriorated since the end of the Cold War. For more than two centuries, the Nordic country maintained a policy of scrupulous non-alignment, on the rationale that doing so would enable Stockholm to claim neutral status in wartime. The country stayed out of both world wars. It avoided alignment with either bloc during the Cold War, even as it remained culturally and economically moored to the Western world. In the years that followed the collapse of the Soviet Union, Sweden expanded its partnership activities with NATO but stopped short of seeking membership.

Russia’s Invasion Changed Sweden’s Calculus

That all changed when Russia invaded Ukraine. This breathtaking act of aggression challenged the logic at the heart of Sweden’s longstanding security policy, which had been grounded on the unspoken assumptions that Russia was unlikely to attack the West and that, if it did so, Sweden would either be unaffected directly or, in a worst-case scenario, could always cast in its lot with NATO. Reasoning thus, Sweden had been able to keep defense spending low and maintain at least a semblance of open lines with Moscow, even as Russia-NATO relations deteriorated under Vladimir Putin.

The invasion of Ukraine, however, showed that Russia was a much less predictable neighbor than Swedes, and indeed many others in the West, had reckoned. The war demonstrated the speed with which Russia could move with large troop formations in pursuit of revisionist geopolitical objectives. It also served as a reminder of the potential for spillover effects from major conflicts that do not initially involve Sweden. Strategically, the war allowed Swedes to imagine Russia making a similar move against, say, a nearby Baltic state that could directly imperil Swedish interests — or even against Sweden itself. Beyond that, Russian barbarism in the war underscored to Swedes just how much they had in common with the rest of the Western world in moral and civilizational terms.

It wasn’t a surprise, therefore, that Sweden, along with next-door Finland, would rethink its accustomed policy and seek membership in NATO. Nor was it surprising that the majority of NATO’s existing members quickly backed Stockholm’s applications. The country is a mature democracy with deep ties to NATO members on both sides of the Atlantic. It has a large defense industry and an advanced military known for its air, naval and cyber capabilities. Since the start of the Ukraine war, Sweden has more than doubled defense spending and is on course to spend a little over 2 percent of GDP on the military this year.

The biggest benefit to NATO, however, is geostrategic in nature. Along with Finland, Sweden adds much-needed strategic depth to the alliance’s northeastern flank. For years, NATO’s greatest liability has been the exposed nature of the Baltic states, Estonia, Latvia and Lithuania. These jut out to form a salient that extends several hundred kilometers away from the rest of NATO. In the event of a Russian attack on one of these countries, the alliance would face serious logistical difficulties sending reinforcements to help them. Russia could seize this vulnerability to grab Baltic territory and present NATO with a fait accompli that could only be reversed with great effort and risk.

Adding Sweden and Finland to NATO significantly reduces this risk. The two Nordic countries extend the alliance’s territory north of the Baltic states all the way to the Russian border. Sweden brings with it the Island of Gotland, which sits athwart the approaches to the Baltic coast like a permanent aircraft carrier. Together, these territories shield the alliance’s previously exposed left flank and impede any Russian attempt at an encircling maneuver against one of the Baltic states.

All of this greatly complicates Russian strategy vis-à-vis NATO. With Sweden and Finland members of the alliance, Russia will have no choice but to devote more attention than it has in the recent past to its northwestern flank. The Nordic region abuts Russia’s Kola peninsula — a slender salient of land where Russia keeps the headquarters of its northern fleet and a large portion of its nuclear arsenal. As long as Finland and Sweden were not members of NATO, Russia could safely divert attention away from this crucial region. That, in turn, enabled it to prioritize military resources for its southwestern flank to support the aggressive drive into Ukraine.

NATO’s Nordic expansion will make this a lot more difficult in the future. Going forward, Russian leaders will have to take stock of their position in the north when contemplating major moves in the south. This is valuable since a major point of strategy is to force your opponent to rethink his preferred strategy. This is true not only with respect to the Baltic but also the Arctic. Seven of the eight members of the Arctic Council are now members of NATO. Going forward, Russia is likely to find it much harder to stealthily militarize this region. 

Sweden, Finland Face Unexpected Obstacles

Given these benefits, it was natural that a majority of NATO members would support Sweden’s bid to join the alliance. What was unexpected was how quickly two NATO members, Turkey and Hungary, moved to transactionalize Sweden’s bid and the lengths to which both went to try to win concessions in exchange for their support. In Turkey’s case, this took the form of a prolonged, public campaign to procure, inter alia, Swedish judicial and legislative action against ethnic Kurds accused of supporting the Kurdistan Workers' Party, or PKK, terrorist organization in Sweden. In Hungary’s case, it took the form of a determined push to elicit promises of support for Hungary in its ongoing rule-of-law disputes with the European Union.

Both Turkey and Hungary added a number of unrelated demands to their wish lists. Turkey wanted the United States to approve Ankara’s purchase of F-16 fighter aircraft — a transaction that had previously been held up by U.S. concerns about Turkey’s purchase of Russia S-400 air defense systems — while Hungary wanted Swedish fighter jets.

Horse-trading of this kind goes on all the time in international politics. It’s not unheard of for NATO Allies to tacitly link their support of decisions in the North Atlantic Council — NATO’s political decision-making body — to outside objectives, or to unilaterally block important initiatives. Nor is such behavior unique to Turkey and Hungary. Greece impeded North Macedonia’s entry into NATO. France has made blockages a veritable art form; at the 2023 Vilnius Leaders Meeting, for example, it squashed plans to open a NATO office in Tokyo.

What made this case different is the urgency of the thing in question — a long-qualified Western country petitioning for membership under exigent circumstances, in a time of war — and the prolonged intransigence of Turkey and Hungary to achieve their objectives.

What Does this Mean for NATO Going Forward?

This episode is likely to have two effects inside NATO. First and most obviously, it could generate lingering distrust toward Turkey and Hungary by other allies. Second, and more seriously, it raises questions about NATO’s political cohesion in a time of crisis. Sweden didn’t make its appeal to join the alliance in a quiet stretch of history; it did so against the backdrop of a major land war and Swedish concerns about an eventual attack on itself by Russia. Many allies may look at its experience and wonder whether a similar situation could occur during an Article 5 crisis in which a member of the alliance is attacked. If that happened, NATO could find itself unable to act due to the stonewalling of one or two members who are determined to extract a national benefit out of the situation. By the time their concerns were satisfied, the damage to Russia’s target and NATO’s credibility would already be done.

There is no easy solution to either problem. NATO is not an international organization, but an alliance among states that operates on consensus among its members. One expects that the months ahead will see quiet diplomacy inside NATO aimed at smoothing frayed relations of a kind that the current secretary-general, Jens Stoltenberg, and his team have proven particularly adept at.

But as NATO celebrates its 75th anniversary and prepares for a new secretary-general, it wouldn’t be a bad idea to reexamine the question of how the alliance makes decisions in a crisis. A NATO with 32 members has many advantages in capabilities and geostrategy over the old NATO at 10 or 20, but speed of action is not one of them. Whether it’s the Nordic accession saga, engagement with Indo-Pacific partners or some allies’ opposition to sending military aid to Ukraine, the consensus principle threatens to paralyze the alliance. This is already doing damage to U.S. interests. In an Article 5 scenario, the results could be catastrophic.

There have been plenty of proposals over the decades about how to ensure that NATO can act quickly when it counts. Already, NATO frequently uses a method called the “silence procedure,” whereby undertakings that aren’t necessarily supported by all members are adopted as long as no ally “breaks silence” and formally opposes them. But clearly, this is not sufficient. One remedy would be to revive the practice from the late Cold War whereby decisions are made by consensus “minus one or two”; another would be to initiate a shift to majority voting. Either way, the idea would be to permit extraordinary decision-making measures in specific circumstances when the stakes are especially high, especially in an Article 5 crisis. The expedited rules could be employed as a back-up to the silence procedure, which as one observer has pointed out “would give a blocking country a strong incentive to make a deal before it loses its bargaining power, strengthening [NATO’s] culture.”

Implementing a change of this kind would require — you guessed it — consensus. But the United States has effectively organized major efforts inside NATO before. It would need to enlist the support of concerned allies who agree with the need for reform — and even then, a certain amount of horse-trading would probably be required. But the end goal would be well worth the effort if it made NATO more capable of protecting its members in a time of mounting geopolitical crisis. In making the case for reform, the United States would probably find willing partners among those members of NATO that are most exposed to the Russian danger, like Sweden and Finland.