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INSIGHTi
NATO: Finland and Sweden
Seek Membership
June 10, 2022
On May 18, 2022, Finland and Sweden applied to join the North Atlantic Treaty Organization (NATO; see
Figure 1). Prompted by growing security concerns about Russia and its 2022 invasion of Ukraine,
Finland’s and Sweden’s decisions mark a historic shift for these traditionally militarily nonaligned
countries. The Biden Administration and many Members of Congress have responded positively to the
prospect of Finland and Sweden joining NATO, arguing that the addition of these two mature
democracies with advanced militaries will enhance security in the Baltic Sea region and the broader Euro-
Atlantic area. NATO enlargement must be approved by all 30 current NATO members; U.S. approval
requires Senate advice and consent.
Finland and Sweden’s NATO Aspirations
Russia’s 2022 war against Ukraine has upended decades of Finnish and Swedish security policy that
sought to balance political, economic, and cultural ties to the West and relations with Russia. After the
Cold War, Finland and Sweden joined the European Union (EU) and established close partnerships with
NATO. Both Finland and Sweden have participated in numerous NATO operations and have capable
military forces that are well integrated and interoperable with those of the alliance. Public support for
NATO accession—and the added security of NATO’s “Article 5” mutual defense clause—has
skyrocketed in both countries since Russia’s invasion of Ukraine; recent polls indicate support at 76% in
Finland and 58% in Sweden.
Finnish and Swedish officials assert that their countries would be “security providers,” enhancing NATO
capabilities and strengthening the alliance’s defense posture in the Baltic region in particular. As called
for by NATO, Finland already spends around 2% of its gross domestic product (GDP) on defense, and
Sweden has committed to increasing its defense spending to meet the 2% goal “as soon as possible.”
Some analysts express concern that Finland and Sweden’s accession could provoke Russia and question
NATO’s ability to defend Finland’s 830-mile border with Russia (which would double NATO’s overall
borders with Russia). Finnish officials contend that Finland has long defended its own borders and would
continue to do so as a NATO member. Finland and Sweden also have strong traditions of societal
resilience and substantial experience dealing with Russian disinformation efforts, cyberattacks, and
hybrid threats.
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Russia’s Reaction
Russia has long opposed closer integration between NATO and Finland and Sweden. Over much of the
past decade, Russia has used aggressive displays of military force (via exercises and territorial air and sea
incursions) to signal its displeasure with enhanced cooperation between Finland and Sweden and NATO.
Immediately prior to Finland’s and Sweden’s NATO applications, Russia’s Foreign Ministry stated,
“Russia will be forced to take retaliatory steps, both of a military-technical and other nature, in order to
neutralize the threats to its national security that arise from this.” Subsequently, however, Russia has
publicly played down the situation. Russian President Vladimir Putin stated that Finnish and Swedish
accession pose “no direct threat for Russia” but emphasized that “expanding military infrastructure” could
be viewed as a threat and could “provoke a response.” Analysts note that Russian losses in Ukraine may
undercut the credibility of a potential Russian military response to Finland’s and Sweden’s NATO
accession.
NATO’s Accession Process and Current Status
NATO allies must agree, by consensus, to accept Finland and Sweden as members. Since NATO’s
creation in 1949, the alliance has grown from 12 founding members to today’s 30 members through eight
rounds of enlargement. The next main step after application is for allied governments to sign accession
protocols to the North Atlantic Treaty. NATO members then ratify the amended treaty according to
national procedures, which vary by country.
NATO’s Secretary General and nearly all allies have welcomed Finland’s and Sweden’s applications, and
many expect the ratification processes could be relatively quick (there is no set time frame, but for recent
enlargements the process has taken about 13 months). Turkey, however, has voiced reservations. Turkey
views Sweden, and to a lesser extent Finland, as sympathetic to the Kurdistan Workers’ Party (or PKK, a
U.S.- and EU-designated terrorist organization). Turkey also objects to both countries’ participation in an
EU-coordinated suspension of arms sales to Turkey since 2019 in response to Turkey’s military
operations in Syria against the YPG (or People’s Protection Units), a PKK-linked group and partner in the
U.S.-led coalition against the Islamic State (ISIS/ISIL). Observers underscore broader Turkish concerns
about U.S. support for the YPG and U.S. sanctions on Turkey in response to its 2019 acquisition of a
Russian S-400 surface-to-air defense system. U.S. and NATO officials express confidence that they will
be able to resolve Turkey’s concerns, but Turkey’s objections could slow the accession process. (Also see
CRS Report R44000, Turkey: Background and U.S. Relations In Brief.)
Role of Congress and U.S. Policy
In the United States, once accession protocols are signed, the Administration sends them to the Senate for
its advice and consent. The treaty would be referred first to the Senate Committee on Foreign Relations,
which then would report it to the Senate, where it requires a vote of two-thirds of Senators present for
passage. If the Senate were to pass a resolution of ratification, the resolution would be transmitted to the
President, who would decide whether to enter the treaty on behalf of the United States. (Also see CRS
Report 98-384, Senate Consideration of Treaties.)
President Biden robustly supports Finland’s and Sweden’s NATO bids and has committed to help “deter
and confront any aggression” during the period before accession. U.S. officials have not provided
specifics on U.S. security assurances, but they may include an increased U.S. military presence and more
joint training exercises. Resolutions of support for Finland’s and Sweden’s NATO accession have been
introduced in both the House (H.Res. 1130) and the Senate (S.Res. 646).
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Figure 1. NATO Countries and Aspirants
Source: CRS Graphics. Map updated June 2022.
Notes: In addition to Finland and Sweden, Bosnia and Herzegovina, Georgia, and Ukraine aspire to NATO membership. In
2008, NATO allies agreed that Georgia and Ukraine would one day become NATO members; Bosnia was granted a
Membership Action Plan in 2010.
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Author Information
Kristin Archick
Andrew S. Bowen
Specialist in European Affairs
Analyst in Russian and European Affairs
Paul Belkin
Analyst in European Affairs
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United
States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However,
as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the
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