Russia’s Invasion of Ukraine: Turkey’s Response and Black Sea Access Issues
link to page 2 
INSIGHTi
Russia’s Invasion of Ukraine: Turkey’s
Response and Black Sea Access Issues
March 11, 2022
Russia’s early 2022 invasion of Ukraine has heightened challenges North Atlantic Treaty Organization
(NATO) ally Turkey faces in balancing relations between the two countries and managing Black Sea
access, with implications for U.S.-Turkey ties. In recent years, Turkey’s links with Russia—especially its
2019 acquisition of a Russian S-400 surface-to-air defense system—have fueled major U.S.-Turkey
tensions, triggering sanctions and reported informal congressional holds on arms sales. Turkey’s
increasing cooperation with Ukraine may have some alignment with U.S. interests in limiting Russia’s
ability to reassert regional dominance. Turkey has made some efforts to mediate between Russia and
Ukraine in the current crisis. For additional context, see CRS Report R44000, Turkey: Background and
U.S. Relations In Brief, by Jim Zanotti and Clayton Thomas.
Assessing Turkey’s Response
In its response to Russia’s invasion, Turkey likely hopes to minimize spillover effects to its national
security and economy. While Turkey has denounced the invasion and supplied Ukraine with armed drone
aircraft and humanitarian assistance, the Turkish government has said Turkey will not join economic
sanctions against Russia. The conflict has already worsened Turkey’s ongoing domestic currency and
inflation crisis, and its economy could be vulnerable to Russian cutoffs of natural gas and wheat exports
or military actions in Syria that create new refugee flows.
In late February, Turkey acknowledged a state of war between Russia and Ukraine, invoking Article 19 of
the 1936 Convention Regarding the Regime of the Straits (the “Montreux Convention”), which bars
belligerent countries’ naval access to and from the Black Sea through the Bosphorus and Dardanelles
Straits (see Figure 1). A few days earlier, Ukraine had called for the Straits’ closure. Shortly after
Turkey’s decision, Secretary of State Antony Blinken expressed appreciation for Turkey’s implementation
of the Convention and support for Ukraine. (The United States is not a party to the convention, but has
complied with its terms since it went into effect in 1936 as a treaty that is reflective of customary
international law.)
Congressional Research Service
https://crsreports.congress.gov
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CRS INSIGHT
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Figure 1. Map of Black Sea Region and Turkish Straits
Turkey’s invocation of Article 19 for the first time since World War II may have limited near-term
military impact. Russia reportedly has naval predominance over Ukraine with its Black Sea fleet and
other ships that transited the Straits before the invasion.
The longer the war continues, the more significant Turkish restrictions on passage could become. An
exception to the Straits’ closure under Article 19 permits access to Russian ships if they are returning to
their designated Black Sea bases, but Turkey’s foreign minister has stated that ships returning to base
“should not be involved in the war.” President Recep Tayyip Erdogan has said that Turkey seeks to avoid
escalation. In March 10 correspondence with CRS, a Turkish official explained that Turkey has advised
all countries to refrain from sending warships through the Straits, but has not formally closed the Straits
to non-belligerent states. Some naval analysts have expressed concern that discouraging other countries
from transit when Russia can return ships to Black Sea bases could undermine the Convention and put
NATO at a disadvantage. One has asserted that Black Sea access is “essential for the alliance’s presence
and security as well as to reassure” allies Romania and Bulgaria.
link to page 4 Congressional Research Service
3
Key U.S. Policy Issues
F-16 Sale and S-400
The ongoing war and its effect on Turkey’s relations with the United States, Russia, and Ukraine, could
influence a pending request by Turkey for upgraded and new F-16 fighter aircraft. Turkey seeks to
modernize its air force after losing access to the F-35 Joint Strike Fighter when it acquired the Russian S-
400 system. Analysts have considered Congress’s role in reviewing the proposed F-16 sale (no formal
notification has occurred to date), how its failure might damage the U.S.-Turkey relationship, and whether
Turkey might turn to Russia or other European countries for fighter aircraft in that case.
Alternatively, it is unclear whether the war and its aftermath might lead Turkey to change its position on
keeping the S-400. Removing the S-400 from Turkey could lead the United States to lift the sanctions
mentioned above, and even allow Turkey to receive F-35s under Section 1245 of P.L. 116-92.
Turkish Military Cooperation with Ukraine
The ongoing war is testing the consequences of Turkish military cooperation with Ukraine. How that
cooperation impacts the war and how Russia responds to it could have implications for U.S. policy.
Turkey has reportedly sold several Turkish-origin Bayraktar TB2 drones (see Figure 2) to Ukraine as part
of deepening bilateral defense cooperation. In recent Turkish-supported military operations in Syria,
Libya, and Nagorno-Karabakh, these drones have established a successful track record in targeting
Russian-made armored vehicles and anti-aircraft systems. Their ability to affect outcomes might be
different in a higher intensity war with Russia. Some claims of successful Ukrainian TB2 strikes on
Russian military targets have emerged during the war, and one report suggested that Ukraine may have
reportedly received additional TB2s in early March.
Congressional Research Service
4
Figure 2. Bayraktar TB2 Drone
Based on outcomes in Ukraine, U.S. officials and lawmakers can assess the benefits and drawbacks of
Turkey-Ukraine military cooperation, and whether to encourage or supplement it in ongoing or future
situations. In the region, Turkey also has recently cultivated closer defense ties with Azerbaijan, Georgia,
and Poland.
Turkish Control over Black Sea Access
Turkey’s control over Black Sea access could affect the balance of forces in a longer Russia-Ukraine war
and beyond. When Turkey itself is not at war, Article 18 of the Montreux Convention places transit limits
on the aggregate tonnage of non-Black Sea country warships, and the duration of their stays.
U.S. officials and lawmakers might evaluate the benefits and drawbacks of Turkish actions affecting
access for Russian and U.S./NATO warships, both during the war and its aftermath. Such evaluations
could inform U.S. efforts to influence Turkish actions and adjust U.S. military deployments. In answering
a question about U.S. Black Sea strategy during a March 8 Senate Foreign Relations Committee hearing,
Under Secretary of State for Political Affairs Victoria Nuland said, “Turkey has taken some very strong
moves since this conflict began under the Montreux Convention to deny warships access.”
Congressional Research Service
5
Author Information
Jim Zanotti
Clayton Thomas
Specialist in Middle Eastern Affairs
Analyst in Middle Eastern 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
permission of the copyright holder if you wish to copy or otherwise use copyrighted material.
IN11885 · VERSION 1 · NEW
INSIGHTi
Russia’s Invasion of Ukraine: Turkey’s
Response and Black Sea Access Issues
March 11, 2022
Russia’s early 2022 invasion of Ukraine has heightened challenges North Atlantic Treaty Organization
(NATO) ally Turkey faces in balancing relations between the two countries and managing Black Sea
access, with implications for U.S.-Turkey ties. In recent years, Turkey’s links with Russia—especially its
2019 acquisition of a Russian S-400 surface-to-air defense system—have fueled major U.S.-Turkey
tensions, triggering sanctions and reported informal congressional holds on arms sales. Turkey’s
increasing cooperation with Ukraine may have some alignment with U.S. interests in limiting Russia’s
ability to reassert regional dominance. Turkey has made some efforts to mediate between Russia and
Ukraine in the current crisis. For additional context, see CRS Report R44000, Turkey: Background and
U.S. Relations In Brief, by Jim Zanotti and Clayton Thomas.
Assessing Turkey’s Response
In its response to Russia’s invasion, Turkey likely hopes to minimize spillover effects to its national
security and economy. While Turkey has denounced the invasion and supplied Ukraine with armed drone
aircraft and humanitarian assistance, the Turkish government has said Turkey will not join economic
sanctions against Russia. The conflict has already worsened Turkey’s ongoing domestic currency and
inflation crisis, and its economy could be vulnerable to Russian cutoffs of natural gas and wheat exports
or military actions in Syria that create new refugee flows.
In late February, Turkey acknowledged a state of war between Russia and Ukraine, invoking Article 19 of
the 1936 Convention Regarding the Regime of the Straits (the “Montreux Convention”), which bars
belligerent countries’ naval access to and from the Black Sea through the Bosphorus and Dardanelles
Straits (see Figure 1). A few days earlier, Ukraine had called for the Straits’ closure. Shortly after
Turkey’s decision, Secretary of State Antony Blinken expressed appreciation for Turkey’s implementation
of the Convention and support for Ukraine. (The United States is not a party to the convention, but has
complied with its terms since it went into effect in 1936 as a treaty that is reflective of customary
international law.)
Congressional Research Service
https://crsreports.congress.gov
IN11885
CRS INSIGHT
Prepared for Members and
Committees of Congress
Congressional Research Service
2
Figure 1. Map of Black Sea Region and Turkish Straits
Turkey’s invocation of Article 19 for the first time since World War II may have limited near-term
military impact. Russia reportedly has naval predominance over Ukraine with its Black Sea fleet and
other ships that transited the Straits before the invasion.
The longer the war continues, the more significant Turkish restrictions on passage could become. An
exception to the Straits’ closure under Article 19 permits access to Russian ships if they are returning to
their designated Black Sea bases, but Turkey’s foreign minister has stated that ships returning to base
“should not be involved in the war.” President Recep Tayyip Erdogan has said that Turkey seeks to avoid
escalation. In March 10 correspondence with CRS, a Turkish official explained that Turkey has advised
all countries to refrain from sending warships through the Straits, but has not formally closed the Straits
to non-belligerent states. Some naval analysts have expressed concern that discouraging other countries
from transit when Russia can return ships to Black Sea bases could undermine the Convention and put
NATO at a disadvantage. One has asserted that Black Sea access is “essential for the alliance’s presence
and security as well as to reassure” allies Romania and Bulgaria.
link to page 4 Congressional Research Service
3
Key U.S. Policy Issues
F-16 Sale and S-400
The ongoing war and its effect on Turkey’s relations with the United States, Russia, and Ukraine, could
influence a pending request by Turkey for upgraded and new F-16 fighter aircraft. Turkey seeks to
modernize its air force after losing access to the F-35 Joint Strike Fighter when it acquired the Russian S-
400 system. Analysts have considered Congress’s role in reviewing the proposed F-16 sale (no formal
notification has occurred to date), how its failure might damage the U.S.-Turkey relationship, and whether
Turkey might turn to Russia or other European countries for fighter aircraft in that case.
Alternatively, it is unclear whether the war and its aftermath might lead Turkey to change its position on
keeping the S-400. Removing the S-400 from Turkey could lead the United States to lift the sanctions
mentioned above, and even allow Turkey to receive F-35s under Section 1245 of P.L. 116-92.
Turkish Military Cooperation with Ukraine
The ongoing war is testing the consequences of Turkish military cooperation with Ukraine. How that
cooperation impacts the war and how Russia responds to it could have implications for U.S. policy.
Turkey has reportedly sold several Turkish-origin Bayraktar TB2 drones (see Figure 2) to Ukraine as part
of deepening bilateral defense cooperation. In recent Turkish-supported military operations in Syria,
Libya, and Nagorno-Karabakh, these drones have established a successful track record in targeting
Russian-made armored vehicles and anti-aircraft systems. Their ability to affect outcomes might be
different in a higher intensity war with Russia. Some claims of successful Ukrainian TB2 strikes on
Russian military targets have emerged during the war, and one report suggested that Ukraine may have
reportedly received additional TB2s in early March.
Congressional Research Service
4
Figure 2. Bayraktar TB2 Drone
Based on outcomes in Ukraine, U.S. officials and lawmakers can assess the benefits and drawbacks of
Turkey-Ukraine military cooperation, and whether to encourage or supplement it in ongoing or future
situations. In the region, Turkey also has recently cultivated closer defense ties with Azerbaijan, Georgia,
and Poland.
Turkish Control over Black Sea Access
Turkey’s control over Black Sea access could affect the balance of forces in a longer Russia-Ukraine war
and beyond. When Turkey itself is not at war, Article 18 of the Montreux Convention places transit limits
on the aggregate tonnage of non-Black Sea country warships, and the duration of their stays.
U.S. officials and lawmakers might evaluate the benefits and drawbacks of Turkish actions affecting
access for Russian and U.S./NATO warships, both during the war and its aftermath. Such evaluations
could inform U.S. efforts to influence Turkish actions and adjust U.S. military deployments. In answering
a question about U.S. Black Sea strategy during a March 8 Senate Foreign Relations Committee hearing,
Under Secretary of State for Political Affairs Victoria Nuland said, “Turkey has taken some very strong
moves since this conflict began under the Montreux Convention to deny warships access.”
Congressional Research Service
5
Author Information
Jim Zanotti
Clayton Thomas
Specialist in Middle Eastern Affairs
Analyst in Middle Eastern 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
permission of the copyright holder if you wish to copy or otherwise use copyrighted material.
IN11885 · VERSION 1 · NEW