Over more than 70 years, the North Atlantic Treaty Organization, or NATO, has grown to an alliance of 30 countries. Founded in 1949 to counterbalance the growing power of the Soviet Union, NATO — long a source of tension between the West and Russia — has reasserted itself as a significant and unified force against Moscow since Russian President Vladimir Putin’s invasion of Ukraine.
Four maps explain how Sweden and Finland could alter NATO’s security
This week Finland and Sweden, traditionally neutral nations, drew closer to joining NATO as the U.S. Senate ratified their bid to join, the 23rd of 30 members to do so. Analysts say the move will transform Europe’s security landscape for years to come — and further strain relations with Russia, which opposes the alliance’s eastern expansion.
The addition of the countries could offer the alliance expanded land, sea and air capabilities. Sweden has a strong navy, which would strengthen NATO’s defenses in the Baltic Sea, and builds its own fighter jets, which it exports to countries around the globe. Finland’s well-funded military maintains mandatory conscription for men. It’s a “whole society approach to thinking about defense,” said Christopher Skaluba, director of the Atlantic Council’s Transatlantic Security Initiative. “They can mobilize hundreds and thousands of their citizens.”
The countries also offer key geographic advantages, which would enhance NATO’s defenses.
A new northern border
Finland's NATO membership would add 800 miles to the alliance's border with Russia.
Kola
Peninsula
Sweden
That border is near the Kola Peninsula, where Russia's nuclear subs and Arctic navy are based.
Finland
Estonia
Latvia
Russia
Lithuania
Rus.
belarus
500 MILES
Poland
Finland's NATO membership would add 800 miles to the alliance's border with Russia.
Barents
Sea
Kola
Peninsula
norway
Sweden
That border is near the Kola Peninsula, where Russia's nuclear subs and Arctic navy are based.
Finland
Baltic
Sea
Estonia
Russia
Latvia
Lithuania
Rus.
belarus
ger.
Poland
500 MILES
Finland's NATO membership would add 800 miles to the alliance's border with Russia.
Barents Sea
Kola
Peninsula
Norwegian Sea
That border is near the Kola Peninsula, where Russia's nuclear subs and Arctic navy are based.
Finland
Sweden
norway
Baltic
Sea
Estonia
Russia
Latvia
DEN.
Lithuania
Rus.
belarus
Germany
Poland
500 MILES
Barents Sea
Kola
Peninsula
Finland's NATO membership would add 800 miles to the alliance's border with Russia.
Norwegian
Sea
That border is near the Kola Peninsula, where Russia's nuclear subs and Arctic navy are based.
Finland
Sweden
norway
Baltic
Sea
Estonia
Russia
Latvia
North Sea
DEn.
Lithuania
Rus.
belarus
u.k.
500 MILES
NETH.
Germany
Poland
Finland’s border with Russia stretches more than 800 miles and is already closely patrolled. The nation’s membership would double the alliance’s land border. “On one hand, this provides NATO with enhanced deterrence as Moscow would need to defend this border,” said Carisa Nietsche, an associate fellow for the Transatlantic Security Program at the Center for a New American Security. “On the other hand, NATO also must protect this border against a Russian attack.”
The Finns remember the Winter War of 1939-1940, when the country incurred great losses fighting back Soviet forces.
“Their relationship with Russia is defined by mistrust,” said Cristina Florea, a historian of Central and Eastern Europe at Cornell University.
Finland’s membership would bring the alliance closer to Russia’s Kola Peninsula, a strategic landmass some 110 miles east of the border where Russia keeps ballistic missile submarines and stores nuclear warheads. The Northern Fleet, tasked with patrolling the Arctic, is based on the peninsula as well.
Increased Baltic presence
To the South, Finland and Sweden’s membership would give the alliance an edge in the Baltic Sea, a strategic waterway bordered by Russia’s St. Petersburg, as well as some of NATO’s most vulnerable members.
Sweden and Finland’s membership would increase NATO’s access to the Baltic Sea.
Sweden
Finland
Baltic
Sea
Russia
Estonia
Latvia
Gotland
Island
Lithuania
Rus.
belarus
Poland
Currently to reinforce Baltic states, NATO has to pass through the Suwalki Gap, a narrow land corridor close to Russian territory.
500 MILES
Sweden and Finland’s membership would increase NATO’s access to the Baltic Sea.
Sweden
norway
Finland
Baltic
Sea
Russia
Estonia
Latvia
DEN.
Gotland
Island
Lithuania
Rus.
belarus
Germany
Poland
Currently to reinforce Baltic states, NATO has to pass through the Suwalki Gap, a narrow land corridor close to Russian territory.
500 MILES
Barents Sea
Sweden and Finland’s membership would increase NATO’s access to the Baltic Sea.
Sweden
Finland
Russia
norway
Helsinki
St. Petersburg
Currently to reinforce Baltic states, NATO has to pass through the Suwalki Gap, a narrow land corridor close to Russian territory.
Stockholm
Baltic
Sea
Estonia
Latvia
Gotland
Island
DEN.
Lithuania
Rus.
belarus
Germany
Poland
500 MILES
Barents Sea
Norwegian Sea
Sweden and Finland’s membership would increase NATO’s access to the Baltic Sea.
Finland
Sweden
norway
Helsinki
St. Petersburg
Stockholm
Russia
Baltic
Sea
Estonia
Currently to reinforce Baltic states, NATO has to pass through the Suwalki Gap, a narrow land corridor close to Russian territory.
Latvia
North Sea
Gotland
Island
DEN.
Lithuania
Rus.
u.k.
500 MILES
belarus
NETH.
Germany
Poland
“NATO’s main mission is keep Russia away from the Baltic states,” Skaluba said, referring to Latvia, Estonia and Lithuania. A growing presence on the Baltic sea’s shores would strengthen security for those countries.
“Swedish and Finnish NATO membership would provide NATO with another reinforcement route through the Baltic Sea,” Nietsche said. “Currently, NATO reinforcement depends on the Suwalki Gap, the narrow corridor separating Kaliningrad and Belarus which Russia could try to close off in a conflict.”
In the middle of the sea lies Gotland, a 109-mile-long Swedish island home to medieval ruins and military fortifications. In April, Sweden announced it would spend $163 million to ramp up its forces on the island, including expanding barracks to house more troops.
An Arctic agenda
Finland and Sweden’s accession to NATO would mean an increase in its presence in the Arctic.
u.s.
More than 50 percent of Arctic Ocean coastline is Russian territory
North pole
Fin.
As members of the Arctic Council, Sweden and Finland’s membership would increase NATO’s footprint in a region Russia sees as vital to its security.
u.s.
More than 50 percent of Arctic Ocean coastline is Russian territory
North pole
Greenland
(Denmark)
Fin.
As members of the Arctic Council, Sweden and Finland’s membership would increase NATO’s footprint in a region Russia sees as vital to its security.
U.S.
U.S.
U.S.
More than 50 percent of Arctic Ocean coastline is Russian territory
North pole
U.S.
Greenland
(DENMARK)
Iceland
GIUK
GAP
Fin.
As members of the Arctic Council, Sweden and Finland’s membership would increase NATO’s footprint in a region Russia sees as vital to its security.
Historically, the GIUK Gap has been strategically crucial as a way to navigate around the otherwise difficult Arctic Ocean.
U.S.
More than 50 percent of Arctic Ocean coastline is Russian territory
U.S.
North pole
Greenland
(DENMARK)
Iceland
Historically, the GIUK Gap has been strategically crucial as a way to navigate around the otherwise difficult Arctic Ocean.
GIUK
GAP
Fin.
As members of the Arctic Council, Sweden and Finland’s membership would increase NATO’s footprint in a region Russia sees as vital to its security.
u.k.
The two countries are members of the Arctic Council, an organization overseeing the northernmost parts of the world whose members include Russia, Canada and the United States. With their membership, “Arctic security would continue to climb on NATO’s agenda,” Nietsche said.
As more than 50 percent of Arctic Ocean coastline is Russian territory, it could climb on Moscow’s agenda too. “They see security in the area as a matter of homeland defense,” Skaluba said.
Military missions from the Kola Peninsula are deployed throughout the Arctic. Sweden and Finland could help monitor that activity, but could also increase the risk of escalation.
“The Arctic is generally considered a success story of cooperation among NATO Arctic nations and Russia, but there are concerns that it will increasingly be a contested area in the security realm, something probably more likely with Sweden and Finland becoming NATO nations,” Skaluba added.
Sources: NATO, The Geography of the International System: The CShapes Dataset (old country borders)
Emily Rauhala contributed to this report.
correction
An earlier version of this article said the the North Atlantic Treaty Organization is 80 years old. It was founded 73 years ago. The article has been corrected.