Sweden has been a member of the North Atlantic Treaty Organization (NATO) since 7 March 2024.
Before applying for NATO membership, Sweden had maintained a policy of neutrality in military affairs since the Napoleonic Wars, after which Sweden adopted a policy of "non-alignment in peace and neutrality in war". The country was neutral in both world wars—though it cooperated with both Germany and Allied nations on various occasions during World War II—and chose not to join NATO when it was founded in 1949. In the mid-1990s, after the Cold War, the country acceded to NATO's Partnership for Peace (PfP) programme, and the European Union (EU). EU membership in practice ended the country's non-alignment, as it included the adoption of common foreign and security policy and, from 2009 onwards, a mutual defence clause. However, public support for NATO accession remained low.
The Russian invasion of Ukraine spurred a shift in public opinion, prompting Sweden to apply for NATO membership alongside Finland on 18 May 2022.
History Background: Swedish neutrality following the Napoleonic wars
Sweden adopted a policy of neutrality following the loss of a large amount of its territory (including Finland) to the Russian Empire during the Napoleonic Wars in 1812. Since 1814, Sweden has not formally declared war, and the country remained neutral even during World War I and World War II. However, during the Russo-Japanese War, the Swedish Army secretly supported Japan with military intelligence and espionage operations inside Russia.
1949–2022: Relations prior to membership application 1949–1991: Swedish neutrality during the Cold War When NATO was founded in 1949, Sweden chose not to join. Instead, the country declared a security policy aiming for non-alignment in peace and neutrality in war. Sweden maintained its policy of neutrality during the Cold War. Former Prime Minister of Sweden Carl Bildt has noted that this policy was in response to fears that if Sweden were to join NATO the Soviet Union might respond by invading neighbouring Finland, with which Sweden had close relations. While independent, Finland adopted a policy of neutrality on foreign affairs during the Cold War in deference to the neighbouring Soviet Union, which was commonly referred to as Finlandization.
1991–1995: Immediate aftermath of the Cold War After the end of the Cold War, an active debate started in Sweden on the question of NATO membership. Sweden joined NATO's Partnership for Peace on 9 May 1994.
1995–2022: Shift from non-alignment within the European Union
In 1995, Sweden acceded to the European Union, thereby aligning with the EU's Common Foreign and Security Policy. This development diminished Sweden's policy of neutrality.
On 18 September 2007, Prime Minister Fredrik Reinfeldt stated that Swedish membership in NATO would require a "very wide" majority in Parliament, including the Social Democrats, and coordination with Finland.
Since the entry into force of the Treaty of Lisbon in 2009, the EU mutual solidarity clause has applied to Sweden along with all other EU member states, and states that all member states must help any other member state under attack:
NATO reported in 2015 that Russia simulated a nuclear attack on Sweden in 2013, and Russian foreign minister Sergey Lavrov threatened in 2016 to "take necessary measures" to prevent Swedish NATO membership. In September 2016 a Swedish government report found that escalating tensions in the Baltic would be a likely catalyst for Sweden joining NATO.
Sweden has been an active participant in NATO-led missions in Bosnia (IFOR and SFOR), Kosovo (KFOR), Afghanistan (ISAF), and Libya (Operation Unified Protector). However, ideological divides were visible in November 2006, when Sweden could either buy two new transport planes or join NATO's plane pool, and in December 2006, when Sweden rejected an invitation to join the NATO Response Force. It later joined in 2013.
Sweden increased cooperation with NATO by agreeing to a host country agreement (signed in 2014 and ratified in 2016), which allows NATO forces to conduct joint training exercises on Swedish soil and to be deployed in Sweden in response to threats to Sweden's national security.
The Swedish left wing, including the Social Democratic Party, the Green Party and the Left Party, along with the nationalist Sweden Democrats, have historically favoured neutrality and non-alignment, while the parties on the right wing have supported NATO membership, especially since the 2014 Annexation of Crimea by the Russian Federation. The centre-right Moderate Party is the largest party by current parliamentary representation in favour of NATO membership, even making it their top election pledge in 2022, and (like the centre-right Liberal Party) has generally supported NATO membership since the end of the Cold War. The centrist Centre Party was opposed to NATO membership until September 2015, when party leadership under Annie Lööf announced that they would motion to change the party policy to push for Sweden to join NATO at their next party conference. The conservative Christian Democrats, also previously opposed, likewise voted to support NATO membership at their October 2015 party meeting. When the nationalist Sweden Democrats adjusted their stance in December 2020 to allow for NATO membership if coordinated with neighbouring Finland and ratified in a referendum, a majority of the members of the Swedish Riksdag for the first time belonged to parties that were open to NATO membership, and a motion to allow for future NATO membership passed the parliament that month by 204 votes to 145.
Support for NATO membership rose between 2012 and 2015, when the SOM Institute showed it growing from 17% to 31%. Events like the annexation of Crimea and reports of Russian submarine activity in 2014, as well as a 2013 report that Sweden could hold out for only a week if attacked, were credited with that rise in support. In October 2014, an opinion poll found for the first time more Swedes in favour of NATO membership (37%) than opposed (36%).
Regular polling by Ipsos documented a decline in Swedes' opposition to membership from 56% in April 2015 to 35% in December 2020, when there was a three-way split, with 33% for membership and 32% undecided. The decline largely corresponded to an increase in undecideds, as the proportion supporting NATO membership had stayed mostly steady since 2014. A poll by Sifo in June 2016 found more Swedes against NATO membership than in favour, while a May 2017 poll by Pew also showed 48% support, and in November 2020, they showed that 65% of Swedes viewed NATO positively, the highest per cent of any non-NATO member polled.
In days following Russia's invasion of Ukraine (24–25 February 2022), a Novus poll conducted found 41% in favour of NATO membership and 35% opposed. The first poll to register majority (51%) support for NATO membership came on 4 March 2022, and support has grown substantially since then.
On 1 March 2024, in the wake of Hungary's approval in the National Assembly, the result of a new poll by Verian was released by TV4, showing a record high support for NATO among Swedes from the media outlet, with 66% in favour. A clear majority also among women now support NATO, after only being clear among men. When it comes to age groups, support is highest among 65 to 79 year olds, with 75%. Among parliament members, the Left Party is the only one where there's still a majority against membership. The Greens have turned in favour, with 50% supporting and only 22% opposing. The Moderate Party holds the strongest support. According to pollster Verian, the increased support was due to the expected imminent membership.
+DatePollsterSupportOpposeNeutralor Lead SOM17% 45%38% 28% SOM29% 34%37% 5% Russia's annexation of Crimea Ipsos28% 56%16% 28% Statista28% 56%15% 28% SOM31% 37%32% 6% FT 37% 36%27% 1% Ipsos33% 47%20% 14% Statista33% 47%20% 14% Sifo 41% 39%20% 2% Statista34% 50%16% 16% Spring 2016 Pew 45% 44%11% 1% Sifo33% 49%18% 16% Statista35% 40%25% 5% Spring 2017 Pew 47% 39%14% 8% Statista31% 44%25% 13% Autumn 2020 Pew 65% 30%5% 35% Ipsos33% 35%32% 2% Demoskop 42% 37%21% 5% Statista 37%35%28% 2% Statista 41%35%24% 6% Russia invades Ukraine 24–25 February 2022 Novus 41% 35%24% 8% Demoskop 51% 27%22% 24% Statista 45%33%22% 12% Statista 58%19%23% 39% Finland and Sweden applied for NATO membership Statista 64%21%15% 43% 4 April 2023Finland accedes to NATOStatista 62%22%16% 40% Kantar Sifo 65%18%17% 47% Verian 65% 18%17% 47% Verian 57% 20%23% 37% Verian 66% 18%16% 48% Sweden accedes to NATO
2022–2024: Accession process following the Russian invasion of Ukraine February – May 2022: Initial response to the invasion Many political positions on NATO membership were reviewed following the 2022 Russian invasion of Ukraine. According to news reports from early March 2022, Finland and Sweden had begun plans to apply for Major non-NATO ally status with the United States. The nationalist Sweden Democrats revised their stance in April 2022 and announced that they would support Swedish membership in NATO if Finland also joins. Around the same time, the ruling Swedish Social Democratic Party announced that they would be conducting an internal dialogue on NATO membership, for a second time in six months. The first time, the party decided to oppose membership. However, on 15 May 2022 they announced that they would now support an application to join the organisation. Of their coalition partners, the Green Party remained opposed, while the Left Party wanted to hold a referendum on the subject, something Prime Minister Magdalena Andersson and the leading opposition Moderate party opposed.
May – June 2022: Declaration of intent, application
Andersson announced that Sweden would apply for NATO membership on 16 May 2022, in coordination with neighboring Finland's application. On 17 May 2022, Ann Linde, Sweden's foreign minister, signed Sweden's application to join NATO. The following day, both countries' applications were formally submitted to NATO Secretary General Jens Stoltenberg.
The European Union announced its support for Finland and Sweden's NATO membership. Croatia's president Zoran Milanović stated that his country should block ratification of Sweden's accession until electoral reform measures are implemented in neighbouring Bosnia and Herzegovina, though the Foreign Minister expressed the government's support for any application. On 28 April 2022, Croatian Foreign Minister Gordan Grlić-Radman announced that Croatia supports Finland and Sweden's applications for membership in NATO. In May 2022, various governments (including those of Albania, Portugal, and the United Kingdom) and their leaders (including the presidents of France and the United States) announced support for both countries' applications.
June 2022 – March 2024: Ratification The ratification process began with the invitation of Finland and Sweden to become members at the NATO summit in Madrid on 29 June 2022. Member negotiations were held on 4 July, and the accession protocols were signed in Brussels on 5 July. The same day, Canada was the first country to ratify both applications. On 9 August 2022, U.S. President Joe Biden signed and approved the decision for Finland and Sweden to apply for membership in NATO. By October 2022, all NATO members except for Hungary and Turkey had completed the processes for ratifying Sweden's accession. On 22 March 2023, the Swedish parliament approved the country's accession to NATO by a vote of 269–37.
NATO Secretary-General Jens Stoltenberg stated in March 2023 that it was "inconceivable" that NATO would not assist Sweden if the latter's security were threatened.
On 4 April 2023, the formal ceremony for Finland's accession to NATO was immediately followed by Foreign Minister of Finland Pekka Haavisto submitting Finland's ratification of Sweden's accession to the organisation.