Defence relations between Poland and Sweden have deepened following Sweden’s accession to NATO, a move driven above all by Russia’s full-scale invasion of Ukraine. According to Sweden’s ambassador to Poland, the two countries can now achieve even more together, particularly in strengthening the security of the Baltic Sea and the wider region.
“We had been discussing NATO membership for a long time, but it was Russia’s full-scale invasion of Ukraine and the deteriorating security situation in Europe that tipped the balance,” Martina Quick, Sweden’s ambassador to Poland, told Newseria.
Sweden had cooperated closely with NATO since 1994, when it joined the Partnership for Peace programme. In 1997, it also became a member of the Euro-Atlantic Partnership Council. Sweden submitted its application to join the Alliance in May 2022 and became a full NATO member on 7 March 2024.
“This has increased our security and also strengthened NATO, because Sweden brings many capabilities to the Alliance, including air, naval and land capabilities, as well as many other assets and a very strong defence industry,” Martina Quick emphasised.
She added that NATO membership had opened a new chapter in Sweden’s relations with European countries, including those in Central and Eastern Europe. As part of NATO’s concept for deterrence and defence of the Euro-Atlantic area, Sweden contributes, among other things, land units to NATO’s Forward Land Forces in Latvia, warships to the Alliance’s Standing Naval Forces, and fighter aircraft for airspace surveillance and rapid response readiness.
“Poland has also begun to show greater interest in the northern part of Europe for many different reasons. Thanks to our NATO membership, cooperation has become easier than before. We are very pleased with closer cooperation with Poland, because we need it in the Baltic Sea to make our shared sea and neighbourhood safer and to strengthen NATO cooperation in this part of Europe,” said the Swedish ambassador to Poland. “We have a very similar view of the threat posed by Russia and of what needs to be done in the Baltic Sea. Through closer cooperation, we can also achieve much more.”
In September 2025, Poland and Sweden signed another agreement on defence cooperation. In November of the same year, the Polish government announced that it had selected the Swedish submarine offer for the Polish Navy. On 12 March this year, at the Naval Port in Gdynia, Polish Defence Minister Władysław Kosiniak-Kamysz met with Swedish Defence Minister Pål Jonson. It was stressed that the new security architecture in the Baltic Sea is based on the Polish-Swedish alliance, including the development of joint capabilities, joint procurement and joint exercises. Joint investment in the defence industry was also discussed.
“What will be the key point of cooperation between Poland and Sweden? There are many different areas. We have already held joint exercises. Last year, for example, the Gotland Sentry exercises took place, during which Polish and Swedish troops trained together on our island of Gotland,” Martina Quick noted.
Gotland Sentry, or GOSE, was the first bilateral SNEX-type exercise ever conducted jointly by Poland and Sweden. The manoeuvres took place in the strategically important Baltic Sea region. In September 2025, more than 100 soldiers from Poland’s 6th Airborne Brigade landed on the Swedish island, practising immediate defence readiness and the rapid deployment of troops. A combat module of the Naval Missile Unit also arrived on Gotland. As part of the exercise, using NSM launchers, soldiers carried out simulated missile strikes against enemy vessels moving across the Baltic Sea.
“As part of CTF Baltic, we are cooperating on command and control structures in the Baltic Sea. We are also working together to counter the shadow fleet, thereby protecting critical infrastructure in the Baltic Sea,” Martina Quick said.
NATO’s Commander Task Force Baltic, or CTF Baltic, is an international structure that has coordinated the activities of naval forces in the Baltic Sea since October 2024.
“There are many things we can do together in our neighbourhood to strengthen ourselves and NATO’s common defence. There is a great deal of critical infrastructure in the Baltic Sea. We have energy assets, power lines, communication cables — many elements of infrastructure on which we all depend,” the Swedish ambassador to Poland emphasised.
Over the past four years, energy and telecommunications cables lying on the seabed of the Baltic Sea have been damaged several times. The incidents affected, among others, connections between Finland and Germany, Finland and Estonia, and Lithuania and Sweden. These cases have raised concerns about acts of sabotage by the so-called shadow fleet. These are primarily Russian-linked vessels, which may sail under different flags and are suspected of involvement in acts of sabotage targeting underwater infrastructure. In May 2025, the Polish military intervened when a vessel classified as part of Russia’s shadow fleet carried out suspicious manoeuvres near undersea power cables.
“Protecting infrastructure, especially now, when the Baltic Sea region is heavily affected by the deteriorating security situation in Europe and Russia’s very aggressive and revanchist policy, is one of our key tasks,” Martina Quick said.
Both Sweden and Poland are members of the Council of the Baltic Sea States, which was established in 1992. Its main tasks include supporting political dialogue and cooperation, as well as setting strategic priorities and directions for regional initiatives in line with the organisation’s long-term priorities. The Council operates through four groups, including a civil protection expert group.
“There is a lot happening in our cooperation. I am referring to various formats, at the bilateral level and within the Council of the Baltic Sea States, which is currently chaired by Poland, where our ministers and officials meet. We have very rapidly developing cooperation between Sweden and Poland in the defence industry, so we are constantly taking further steps,” the Swedish ambassador to Poland explained.
