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INSIGHTi
Russia’s Invasion of Ukraine:
NATO Response
Updated March 15, 2022
The 30-member North Atlantic Treaty Organization (NATO; see Figure 1) has condemned Russia’s
February 2022 invasion of Ukraine, which it has characterized as an effort to “destroy the entire rules-
based international order, on which our peace and security depend” and the “most dangerous moment in
European security in a generation.” Underscoring its role as a defensive alliance, NATO has joined the
United States in declaring that it would not deploy forces to Ukraine, which is not a NATO member.
NATO has, however, significantly enhanced its defensive force posture in the eastern part of the alliance
and reiterated its solidarity with Ukraine.
NATO officials also have expressed support for substantial bilateral assistance, including arms transfers,
being provided to Ukraine by NATO members since the invasion. According to some reports, arms
transfers from NATO allies to Ukraine have included 17,000 anti-tank missiles and 2,000 Stinger anti-
aircraft missiles as of early March.
Enhanced Deterrence
Since Russia’s first invasion of Ukraine in 2014, NATO has renewed its focus on territorial defense and
deterring Russian aggression, including by deploying battlegroups, increasing military exercises and
training, and enhancing air policing over the three Baltic states (Estonia, Latvia, and Lithuania) and
Bulgaria and Romania. The cornerstone of these efforts is an Enhanced Forward Presence (EFP) of four
multinational battle groups stationed in the Baltic states and Poland. The battle groups, which as of early
February 2022 collectively totaled about 5,000 soldiers, are led by the United Kingdom (Estonia), Canada
(Latvia), Germany (Lithuania), and the United States (Poland). NATO also has established a
Multinational Division Southeast headquartered in Romania to coordinate a Tailored Forward Presence
(TFP) in the Black Sea region.
Since the February invasion, the United States and its NATO allies have collectively more than doubled
the alliance force presence in Eastern Europe, with more than 130 allied fighter jets now on high alert in
the eastern part of the alliance and more than 200 allied ships at sea from the Baltic Sea to the
Mediterranean. In addition to U.S. deployments (see below), new deployments to NATO’s forward
presence include more than 1,000 soldiers and additional fighter jets from the UK; 500 French troops in
Romania; 350 additional German troops in Lithuania and a German-Dutch Patriot air defense system in
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Slovakia; and additional fighter jets, ships, and troops from Belgium, Canada, Italy, the Netherlands, and
Spain, among others.
On February 24, NATO announced that the alliance had activated defense plans that would allow military
commanders to deploy elements of the NATO Response Force (NRF), a multinational rapid-reaction force
of 40,000 personnel with land, air, maritime, and special operations components. In January 2022, the
Biden Administration announced that 8,500 U.S. soldiers would be placed on high readiness for possible
deployment to the NRF.
Despite these measures, NATO members remain concerned about the potential for a wider conflict. Even
prior to Russia’s invasion, some studies of NATO’s force posture concluded that NATO forces would
struggle to defend NATO’s most vulnerable allies—for example, the Baltic states—from a Russian attack.
U.S. Deterrence Deployments
Following Russia’s 2014 occupation of Crimea, the Obama Administration increased the U.S. military
presence in Europe under the European Reassurance Initiative, later renamed the European Deterrence
Initiative (EDI). The cornerstone of EDI has been Operation Atlantic Resolve, the rotational deployment
of approximately 7,000 U.S. armed forces in Europe, including an Armored Brigade Combat Team (BCT)
in Central and Eastern Europe. According to the Department of Defense, an additional 15,000 U.S.
soldiers have deployed to Europe since early February 2022 to augment defense and deterrence efforts,
bringing the total U.S. force posture in Europe, including permanently stationed forces, to approximately
100,000 military personnel. The new deployments bring the total U.S. military presence in Poland to
about 9,500—including 800 soldiers deployed to the U.S.-led NATO battlegroup—and in Romania to
about 1,900. In addition, about 800 U.S. soldiers and 20 attack helicopters have been deployed to the
Baltic region, along with eight F-35 joint strike fighters deployed to NATO’s eastern flank. An additional
7,000 U.S. soldiers, including a BCT, have deployed to Germany to reinforce deterrence efforts, including
as part of the NRF.
Considerations for Congress
Members of Congress have condemned Russia’s invasion of Ukraine and are considering numerous
policy responses, including with respect to NATO’s role. Key considerations include the following:
NATO and U.S. Force Posture in Europe. Russia’s invasion has heightened concerns
about NATO’s capacity to defend NATO member states, particularly the Baltic states,
from a possible Russian military attack. Key factors to consider could include NATO
member states’ willingness and capacity to respond to an intentional or inadvertent attack
on NATO member states, and what form that response may take; the U.S. role in
responding to a possible attack; and sustaining alliance cohesion regarding the
appropriate response to a potential attack.
Future of NATO-Russia Relations. NATO’s current Strategic Concept, adopted in
2010, outlines a desire for “strategic partnership” with Russia. As the alliance prepares to
adopt a new Strategic Concept in June 2022, U.S. policymakers could advocate
fundamental changes to NATO’s approach to Russia, such as emphasizing defense and
deterrence over engagement. This may include reassessing NATO’s prior willingness to
negotiate with Russia on European security arrangements, including arms control and the
alliance’s nuclear force posture.
NATO’s Role in Supporting Ukraine. With support from Congress, NATO has
consistently rejected Russian demands for a halt to NATO’s “open door” enlargement
policy. Russia’s invasion of a NATO aspirant that borders four NATO members could
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prompt discussions within the alliance on NATO’s obligations to Ukraine; its relations
with other aspirants, such as Georgia; and the future of NATO enlargement. With respect
to Ukraine, some Members of Congress have called for more direct support to counter
Russia and defend Ukraine, despite Ukraine not being an alliance member. Others,
including the Administration, remain cautious about any options that could escalate the
conflict.
Figure 1. NATO Europe
Source: Map created by CRS.
Notes: NATO members Canada and the United States are not depicted.
Author Information
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
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