Sweden’s defense minister told Business Insider that his country, the newest NATO ally, has “unique capabilities to strengthen the alliance.”
Pål Jonson highlighted Sweden’s “sub-arctic capabilities” and singled out Swedish submarines operating in the Baltic Sea.
Sweden joined NATO in March 2024, abandoning decades of neutrality in response to Russia’s invasion of Ukraine. Its military has been largely built with a threat from Russia in mind, and it is now one of many European countries warning Russia could attack elsewhere on the continent.
Sweden’s navy has three advanced Gotland-class diesel-electric submarines and a fourth older one due to be retired when it gets two new models expected starting in 2027.
Though they aren’t nuclear-powered like US submarines, these submarines are quite capable. They have proven themselves against Western navies in exercises.
Professor Basil Germond, a maritime security expert at the UK’s Lancaster University, told BI that in the case of war, with Sweden now a part of the alliance, “NATO will be in a much better position in the Baltic Sea than Russia because of the concentration of power around the sea and their ability to close the sea to Russian activities.”
Powerful submarines
Sweden’s submarines are small, silent, and can stay underwater for long stretches. The capabilities of the boats allowed one to “defeat” an American aircraft carrier, assets that are normally well-defended, in a military exercise.
Sweden’s HSMS Gotland “sank” USS Ronald Reagan in a 2005 wargame that pitted a carrier task force against the Swedish boat in an anti-submarine warfare exercise.
Sweden operates conventional Gotland-class submarines, which Steven Horrell, a former US naval intelligence officer and now a naval warfare expert at the Center for European Policy Analysis, described to BI as “quieter than even a US nuclear class submarine.”
Bryan Clark, a former submariner and naval operations expert at the Hudson Institute, described Sweden’s submarines as “very quiet.”
“That means they can operate undetected,” he said. “They can patrol areas like the Baltic in particular, without the adversary forces knowing they’re there.”
Clark called the submarines a “big asset” for NATO.
Many NATO allies around the Baltic Sea have far less maritime capability. Sweden’s Submarine Flotilla Commander Fredrik Linden told Reuters in 2023 that Sweden’s navy has “regional expertise, which fills a critical gap, expertise that NATO doesn’t have.”
Jonson said Sweden has “unique capabilities to operate in the Baltic Sea under the surface, on the surface, and in the air.” He added that the waterway is “a rather unique operational environment.”
“The number of vessels at any time is about 4,500,” the minister said of the strategic waters of the Baltic Sea. “That has increased significantly during the last decades and after the full-scale invasion broke out.”
A strategic sea
Sweden knows the Baltic Sea well. Jonson said that operating there is “something we’ve been doing for hundreds of years, and we like to think that we know the Baltic Sea inside out.”
Located in northern Europe, the waterway is surrounded by Russia and NATO allies Denmark, Estonia, Finland, Germany, Latvia, Lithuania, and Poland and is strategically important both to NATO and the Russians.
It is a key trade and telecommunications route. Jonson, Sweden’s defense minister, described the sea as “an important lane of communication.”
Russia’s war, which Moscow purportedly started with the intention to limit NATO expansion, has seen the Baltic become what some alliance members have called a “NATO sea” with Finland and Sweden joining as allies.
In the Ukraine war, Russia has used its warships and subs to launch missiles at cities and critical infrastructure. Ukraine has, however, been able to damage many of Russia’s vessels using its naval drones, driving away Russia’s Black Sea Fleet from its headquarters in Crimea.
That has made St. Petersburg more important as one of only a few Russian ports that don’t become inaccessible in the winter. If Russia wanted to threaten Europe, the Baltic Sea could become a strategically significant battleground.
For NATO, maintaining a greater maritime deterrence posture in the Baltic Sea is critical.
Made for this threat
The Gotland class submarines have been around for a while now, but they have been repeatedly updated to maintain their top-tier combat capabilities.
The Swedish boats feature a unique air-independent propulsion system powered by Stirling-cycle external-combustion engines, an X rudder for maneuverability, and four heavyweight torpedo tubes and two lightweight torpedo tubes. They’re stealthy assets that can combat surface ships and subs, as well as lay mines.
Horrell called them perfect for a sea with “smaller inlets, small islands, small shallow waters.”
“When you throw in there that it’s home waters that someone has been operating in for years and years as an individual, individual officers, individual crews, crews as a team, you know, that makes a huge difference and brings a lot of capabilities,” he added.
Clark said Sweden tends “to operate primarily in that Baltic Sea, North Sea region, which is a lot of relatively shallow water and a lot of coastline, a lot of little inlets and fjords.”
He said Sweden typically focuses on “submarines and coastal warfare” while Finland focuses more on sea denial, with assets like mine layers. “Between the two of them,” he said, “they could pin Russian forces inside of Russian waters pretty effectively.”
Western officials have raised concerns about Baltic Sea security in response to severed undersea cables.
Sweden is stepping up its actions there, buying more surface vessels. Other allies are, too. Denmark is buying dozens more ships amid rising threats in the Baltic Sea and the Arctic.
Sweden and many of its neighbors warn Russia could attack elsewhere in Europe, beyond Ukraine.
It has increased its defense spending and wants allies to do the same. Jonson said “we doubled our own defense investment in five years, and we’re now 2.4% of GDP and we have a trajectory going up to even further.”
