Russian Military Mobilization on Ukraine’s Borders and in Occupied Crimea
INSIGHTi
Russian Military Mobilization on Ukraine’s
Borders and in Occupied Crimea
April 27, 2021
In March 2021, Russia began massing troops on the Ukrainian border and in Ukraine’s occupied Crimea
region. Observers have disagreed about whether Russia is preparing for a future invasion or engaging in
coercive signaling. Russia continued to build up its forces in April, dismissing concerns and stating that it
was conducting military exercises. On April 22, Russia announced that most units would return to their
permanent bases but some would remain deployed through upcoming exercises in September. Which
units wil remain and which wil return to their bases remains to be seen. Congress has expressed support
for Ukraine’s territorial integrity and for deterring Russian aggression.
Russian Troop Deployments
Despite a cease-fire negotiated in July 2020, fighting between Ukrainian armed forces and Russia-led
rebel fighters in the Donbas region of eastern Ukraine has increased since February 2021. Both sides have
reported increased casualties and cease-fire violations, including the use of heavy artil ery. International
monitors have reported numerous cease-fire violations, denial of passage along the contact line, and
electronic interference with unmanned aerial vehicles used to monitor the cease-fire.
As tensions increased, Russia began conducting military exercises on Ukraine’s border and in Ukraine’s
occupied Crimea region in March 2021. At the same time, Russia accused Ukraine of preparing an
offensive to retake separatist regions in the Donbas, without offering evidence of such a buildup. Russia
increased its military posture in Crimea, where airborne troops conducted dril s, and Russian Defense
Minister Sergei Shoigu announced plans to relocate Russia’s 56th Air Assault Brigade to Feodosia,
Crimea. Russia conducted additional exercises on the Ukrainian border, and reports indicated that Russian
troops failed to return to their bases after exercises concluded. This amassing caused significant concern
in Ukraine and among Western governments, with U.S. European Command raising its watch level to
“potential imminent crisis.” In March and April, U.S. Secretary of State Antony Blinken, Secretary of
Defense Lloyd Austin, and Chairman of the Joint Chiefs of Staff General Mark Mil ey held cal s with
their Ukrainian counterparts. President Biden held a cal with Ukrainian President Volodymyr Zelensky
on April 2.
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In April 2021, Russia continued to move military
Figure 1. Russia-Ukraine Border
forces both on Ukraine’s border and in Crimea.
Social media, open sources, and media reports
documented troops moving toward the Ukrainian
border and Crimea from Russia’s Southern and
Central Military Districts. Russia reported
conducting further military exercises. Russia’s
military buildup, however, exceeded its reported
exercises, and justifications came only after
Ukraine and Western governments expressed
concern. On April 13, Defense Minister Shoigu
stated that Russia had redeployed units from two
armies and three airborne units to its western
border as part of a readiness exercise.
Source: Congressional Research Service.
In addition to the size of the buildup, the
composition of forces raised concerns, as did reports of heavy artil ery, tanks, electronic warfare assets,
and combat aircraft moving toward the Ukrainian border, as wel as 9K720 Iskander short-range bal istic
missiles. Satel ite imagery and media reporting focused primarily on the Pogonovo training area, outside
Voronezh on the Ukrainian border, and other units were identified in Crimea, including at the Opuk
training range. More recently, Russia moved significant naval forces, including landing ships, and air
assets to conduct exercises in Crimea.
U.S. officials estimated that the size of Russian troops deployed near Ukraine and in Crimea exceeded the
number that forcibly occupied Crimea in 2014. Recently, EU officials estimated that Russia had more
than 100,000 troops deployed, and Ukrainian authorities stated that they expected Russian forces to
approach 120,000 by the end of April—although these estimates were made before Moscow announced
that military units would return to their bases.
Some analysts note that Russia’s military posture does not appear poised to launch an offensive. Most
forces are based outside Voronezh and would require time to mobilize for operations. Moving troops
closer to the border would provide an indication of a possible invasion. Additional y, analysts have noted
the limited presence of logistics and support capabilities, with many skeptical there was sufficient support
for offensive operations.
Possible Russian Intentions
Russia’s intentions behind its troop movements remain unclear. Two possible ambitious goals include
seizing Ukrainian territory north of Crimea to solve Crimea’s water crisis or introducing more Russian
troops into eastern Ukraine and formal y annexing the region. Both options would entail significant
forces, however, and likely would result in large casualties.
Many observers argue that rather than planning for these goals, Russia is engaging in some form of
coercive signaling. The buildup was public, with little effort to hide troops and equipment moving
towards Ukraine. It also was gradual, increasing over several weeks. It is unclear if Russia was signaling
to Ukraine to restart Minsk negotiations regarding eastern Ukraine, warning the new Biden
Administration and Western audiences of the potential consequences of policies the Kremlin views as
anti-Russian, distracting from domestic controversies such as the imprisonment of Russian opposition
figure Alexei Navalny, or al the above.
At the same time, observers expressed concerns that movement of new units and equipment to the border
was a possible indication of offensive intent. Since 2015, Russia has reformed and bolstered its force
posture on the Ukrainian border, partly to deter any future Ukrainian military offensive. On April 14,
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Central Intel igence Agency Director Wil iam Burns stated to the Senate Intel igence Committee that the
“buildup has reached the point where ... it also could provide the basis for limited military incursions.”
On April 21, Russian President Vladimir Putin stated that although Russia prefers peace, foreign
adversaries should not “cross the red line in respect to Russia,” or “Russia’s response wil be
asymmetrical, quick and tough.” On April 22, Defense Minister Shoigu announced that exercises were
complete and most units would return to their permanent bases. Some units, however, would remain at the
Pogonovo training range, outside of Voronezh, through the upcoming Zapad military exercises in
September. As a result, significant Russian forces likely wil remain close to the Ukrainian border for the
near future, al owing Russia to threaten escalation through the summer.
Author Information
Andrew S. Bowen
Analyst in Russian and European Affairs
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