NATO officials assured Finland and Sweden when they applied together for membership in May 2022 that their process would be the fastest in history. And, in fact, it finally has been, but nearly one year since Finland's rapid accession in April 2023 has been nerve-wracking for the Swedish government, which had hoped the duo's accession would be a tandem one like the application. But opposition from Turkey and Hungary meant Sweden had to accept that long delay before being allowed under NATO's security umbrella.

Oscar Jonsson, a researcher with the Swedish Defence University, says having declared its desire to join but being stalled by would-be allies was the "worst place" for Sweden to be stranded, even temporarily.

"If you look at just recent empirics, you can see that Russia has invaded two states that it perceived to be on the way into NATO," he told DW, referring to Georgia and Ukraine, "but zero NATO member states."

Turkish-Hungarian holdouts

It took some 20 months to gain the approval of the Turkish parliament and another few weeks for Hungary's. Each required extra diplomacy and, as it turned out in both cases, coincidental or not fighter-jet deals.

Turkey's green light for Sweden came only after it was assured of the long-stalled acquisition of F-16s from the United States — which waited to confirm until Turkey's required documents arrived in Washington, DC. For Hungary, it was four additional JAS-Gripens from Sweden before the parliament took its vote on February 26.                

But then new Hungarian President Tamas Sulyok made ratifying this decision his very first act in office on March 5.  

Article 5, finally

Sweden had concluded multiple bilateral security arrangements with NATO countries over the years based on its intention to remain outside a military alliance, but none of them had the binding nature of NATO's Article 5 "all for one and one for all" guarantee.

Defense Minister Pal Jonson, who previously was the head of the Swedish parliament's defense committee, advocated membership for decades by saying his country "can hope, we can assume, we can wish that we get the support from NATO [in case of attack], but we cannot know until we join the alliance." 

But that concern was not enough for the majority of the Swedish population until Russian President Vladimir Putin launched war on Ukraine — and until neighboring Finland made clear it would waste no time in seeking membership.

Expert: Swedish "special status" already long gone

Oscar Jonsson says while the NATO application was portrayed by many inside and outside Sweden as the abandonment of the country's cherished self-image as a "neutral" and military non-aligned nation, it actually wasn't.

"It was a bigger civilizational shift to join the European Union," he says of that 1995 decision, "which has supra-national authority and can create its own laws, which affects the Swedish way of life in a much more tangible way." But NATO has no such authority to affect legislation. 

In addition, Jonsson notes Sweden's military has participated in virtually every NATO military operation since the 1990s, after joining the organization's "Partnership for Peace" in 1994, and it has long hosted NATO military exercises.

Swedish solidarity certain now

But if Swedish NATO advocates were worried because they didn't have an Article 5 guarantee before membership, allies were also a bit uncomfortable with the lack of a Swedish guarantee as to how it would behave in case of a crisis.

Jim Townsend is now an analyst with the Center for a New American Security (CNAS) but his early career in the Pentagon was spent mostly on Europe and NATO policy, and specifically on the Nordic countries. He told DW that Swedish accession, along with Finland's, is "critical for NATO" and for himself, "it feels like Christmas" after a lifetime spent integrating Nordic and NATO militaries as much as was possible under the circumstances.

Townsend explained that, as closely aligned as Sweden, Finland and the US were, the three countries couldn't have taken anything for granted if a crisis broke out. He said when US military planners were looking at a military confrontation with Russia in the Baltic-Nordic area, "you never really knew what would happen in terms of [Sweden/Finland] giving us permission to use their airspace or were they going to sit it out … you never knew."

Russian rue

With any ambiguity erased, Townsend said, it's for Russian planners to worry now. Swedish accession reinforces NATO's presence in the Arctic, where he notes, Russia has its "most sensitive military establishment … their submarine-launched ballistic missiles … their strategic bombers and that's where they do a lot of their experimentation."

In addition to geostrategic advantages, Sweden brings superb military assets to NATO's potential arsenal. The Washington-based Wilson Center ticks off three major benefits to the alliance:

• Sweden's defense industry, one of the largest in Europe, producing some of the "most sophisticated equipment on the market"
• the "high level of technological competence in Sweden's private sector" coupled with "large quantities of critical minerals—such as iron ore and rare earth metals—which are vital for the defense industry" 
• Sweden's air force, the largest of the Nordic countries and one of the largest in Europe.

Stockholm aces stress tests

Robert Pszczel, the last NATO diplomat posted to Russia before the liaison office in Moscow was closed due to deteriorating relations, told DW there's another important element of Swedish membership — a "very thorough, very realistic understanding of the threat posed by Putin" which translates into high levels of resilience and preparedness training in Swedish society.

"The big thing is to be aware of this, not to panic, but do everything necessary to prepare oneself for this," Pszczel said. "That's a major contribution as well."

Especially because Pszczel expects that Sweden's membership may provoke more hybrid attacks from Russia now that, to quote a popular phrase, the Baltic Sea has become a NATO lake. "[Swedish accession] is a big failure for Russia in terms of politics because this is something which they did not want, that's for sure," he said.

Edited by: Andreas Illmer