U.S. Leadership Needed to Improve Maritime Security in the Black Sea and the Sea of Azov

This spring, Russia has been conducting a sizeable military buildup along its border with Ukraine and in occupied Crimea. Most of these deployments seem spontaneous and unrelated to any scheduled training exercises. Russia’s activity has not been limited to the land.

There has also been a Russian buildup at sea. Recently, four Russian warships from the Baltic fleet have moved to the Black Sea. In addition, 15 vessels from the Caspian flotilla have just arrived in the Sea of Azov.

This means a total of at least 50 Russian warships are now operating in the waters around Ukraine.“Moscow Moving 15 Warships from Caspian Sea to Waters off Ukraine,” Eurasia Daily Monitor, Vol.

18, No.

59 (April 13, 2021), https://jamestown.org/program/moscow-moving-15-warships-from-caspian-sea-to-waters-off-ukraine/ (accessed April 16, 2021).


Since Russia’s annexation of Crimea in 2014, Moscow has essentially turned the Sea of Azov into a Russian lake, with one exception: Ukraine’s port at Mariupol. If this port were neutralized, Russia would then move on in the hope of a similar outcome in the Black Sea. This is a direct threat to U.S. and NATO security interests.

Many of the recent NATO-level initiatives regarding the Black Sea have not met expectations. The economic, security, and political importance of the Black Sea and the broader region is only now becoming more important. Often overlooked in the debate about the Black Sea is the situation in the Sea of Azov.

This small, shallow body of water, connected to the Black Sea by a narrow strait, has been important for centuries. The U.S. needs to be a leader inside NATO to help Ukraine enhance security in the Black Sea and the Sea of Azov. The U.S. can do this by: (1) increasing its naval presence in the Black Sea; (2) pushing for a bigger NATO maritime presence in the Black Sea; (3) conducting a Limits of the Sea Review on the Sea of Azov; (4) consider conducting a Freedom of Navigation Operation (FONOP) through the Kerch Strait; (5) work closely with Black Sea NATO members Bulgaria, Romania, and Turkey to improve regional security; and (6) improving Ukraine’s and Georgia’s maritime and naval capabilities.

Importance of the Black Sea

The Black Sea sits at an important crossroads between Europe, Asia, and the Caucasus.Any comprehensive Black Sea strategy must include all domains, including land, air, and maritime.

However, this Backgrounder is focused specifically and narrowly on the maritime domain.

“>REF Many important oil and gas pipelines, as well as fiber optic cables, crisscross the sea. Throughout the history of the region, the Black Sea has proven to be geopolitically and economically important.

Even for a country located thousands of miles away, like the United States, the Black Sea is important. For the U.S., the Black Sea’s strategic importance is primarily derived from two issues.

The first is America’s treaty obligations under NATO. Three of six Black Sea countries (Bulgaria, Romania, and Turkey) are in NATO and fall under the alliance’s security guarantee. Another two countries (Georgia and Ukraine) participate in NATO’s Partnership for Peace program.

Second, one of America’s biggest geopolitical competitors and adversaries, Russia, is very active in the region, constantly undermining the interests of the U.S. and its allies. It is also worth noting that Black Sea countries have demonstrated a greater political will to deploy troops in support of NATO operations than countries in other regions. For example, over the past few years, Bulgaria, Georgia, Romania, Turkey, and Ukraine collectively contributed one-third of all the European forces serving in NATO’s Resolute Support mission in Afghanistan.

In the Black Sea, the main U.S. goals are:

  • A sovereign Black Sea. Across the Black Sea region, national sovereignty is being undermined by illegal occupation. Between Russia’s illegal occupation of Georgia’s Abkhazia region and Ukraine’s Crimea, there are an estimated 13,700 square miles of territory under illegal occupation in the Black Sea region. Moscow uses these occupations to exert influence in the region.
  • A secureBlack Sea. The U.S. should promote policies in the Black Sea region that support regional security.

    This includes helping NATO members and partners in the Black Sea to bolster their own naval capabilities. A secure Black Sea region offers many economic, trade, and energy opportunities–and also encourages much-needed foreign investment in the region.

  • A self-governing Black Sea region. It is in America’s interests that Black Sea countries remain self-governing with little or no influence from outside or regional powers. This is particularly true of Russia’s malign influence and hybrid tactics in Georgia and Ukraine.

    Strong and stable governments resilient to outside influence are in America’s interest in the region.


Russian Dominance

For Russia, domination of the Black Sea region has always been considered a matter of national survival. Russian Black Sea ports, being Russia’s only warm water ports, have always served the economic interests of Russia. For example, on the eve of World War I, 50 percent of all Russian exports and 90 percent of Russian agriculture exports, passed through the Bosphorus Strait out of the Black Sea.Eugene Rogan, The Fall of the Ottomans (New York: Basic Books, 2015), p.


“>REF Today, an oil tanker passes through the Bosphorus out of the Black Sea every 15 minutes carrying Russian oil or Kazakh oil. (The latter, of course, transits Russia so that Moscow can collect transit fees.)Shamseer Mambra, 6 Bosphorus Strait Facts You Must Know, Marine Insight, updated on August 6, 2020, https://www.marineinsight.com/know-more/6-bosphorus-strait-facts-you-must-know (accessed April 14, 2020).”>REF

Russia’s annexation of Crimea in 2014 was an unprecedented act of foreign-state aggression in the 21st century. It was the first time since 1945 that borders in Europe had been changed using military force. The annexation has de facto cut Ukraine’s coastline in half and has helped Moscow with its long-term goal of turning the Black Sea into a Russian-controlled lake.

Additionally, Russia has claimed rights to underwater resources off the Crimean Peninsula that previously belonged to Ukraine. Russia has taken steps to strengthen its grip on Crimea through a major effort at increasing capabilities, especially anti-access and area-denial (A2/AD) capabilities. As the 2021 Index of U.S.

Military Strength notes:

Russia has deployed 28,000 troops to Crimea and has embarked on a major program to build housing, restore airfields, and install new radars there. Deployment of the Monolit-B radar system, for instance, which has a passive range of 450 kilometers, “provides the Russian military with an excellent real-time picture of the positions of foreign surface vessels operating in the Black Sea.” In addition, “Russian equipment there includes 40 main battle tanks, 680 armored personnel carriers and 174 artillery systems of various kinds” along with 113 combat aircraft. In March 2019, Russia announced the deployment of nuclear-capable Tupolev Tu-22M3 strategic bombers to Gvardeyskoye air base in occupied Crimea.“Russia,” in Dakota L.

Wood, ed., 2021 Index of U.S. Military Strength (Washington, DC: Heritage Foundation Press, 2021), https://www.heritage.org/2021-index-us-military-strength/assessing-threats-us-vital-interests/russia (accessed April 19, 2021).


In addition, Russia has deployed five S-400 air defense systems with a potential range of around 250 miles to Crimea.Michael Petersen, “The Naval Power Shift in the Black Sea,” War on the Rocks, January 9, 2019, https://warontherocks.com/2019/01/the-naval-power-shift-in-the-black-sea/ (accessed April 5, 2021).

“>REF Furthermore, “local capabilities have been strengthened by the Pantsir-S1 (SA-22 Greyhound) short-to-medium-range surface-to-air missile and anti-aircraft artillery weapons system, which particularly complements the S-400.”Sergey Sukhankin, “Russia Pours More Military Hardware into ‘Fortress Crimea,'” Eurasia Daily Monitor, Vol.

14, No.

147 (November 14, 2017), https://jamestown.org/program/russia-pours-military-hardware-fortress-crimea/ (accessed April 5, 2021).”>REF Russia also deploys the Bastion P coastal defenses armed with the P-800 Oniks anti-ship cruise missile, which “has a range of up to 185 miles and travels at nearly mach 2.5, making it extraordinarily difficult to defeat with kinetic means.”Petersen, “The Naval Power Shift in the Black Sea.””>REF

The importance of the Black Sea for Russia goes beyond the region. Russia also uses Crimea as a springboard for military operations farther abroad, such as in Syria, Libya, and the Arabian Sea.

This growing naval presence is being further underwritten by the late 2020 access deal to Port Sudan for up to four warships, effective through 2045, and includes allowance for nuclear-powered ship visits.Vladimir Isachenkov, “Russia Has Signed an Agreement to Establish a Navy Base on the Red Sea for at Least 25 Years,” Associated Press, December 9, 2020, https://www.businessinsider.com/russia-agreement-for-navy-base-in-sudan-for-25-years-2020-12 (accessed April 14, 2021).

“>REF For example, Russia has used its Black Sea presence in occupied Crimea to launch and support naval operations in support of Syrian President Bashar al-Assad.

In the early days of Moscow’s intervention in Syria, the Moskva, a Russian navy-guided missile cruiser, played a vital role in providing air defense for Russian forces.Matthew Chance, “On Board the Warship Moskva: The Naval Power Behind Russia’s Air War in Syria,” CNN, December 17, 2015, https://www.cnn.com/2015/12/17/middleeast/syria-russian-warship-moskva/index.html (accessed April 14, 2021).

“>REF Hundreds of thousands of tons of grain and wheat have been shipped from Crimea to Syria to help the Assad regime’s food shortage problems.Jonathan Saul and Polina Devitt, “Syria’s Assad Gets Food Lifeline from Crimea,” Reuters, June 21, 2018, https://www.reuters.com/article/us-mideast-crisis-syria-crimea-insight/syrias-assad-gets-food-lifeline-from-crimea-idUSKBN1JH1F7 (accessed April 14, 2021).”>REF Hundreds of trips have been made between Crimea’s port city of Sevastopol and the Russian naval base in Tartus, Syria, to transport military hardware and resupplies.Gulliver Cragg and Elena Volochine, “The Crimean Port of Sevastopol, a Strategic Link Between Russia and Syria,” France 24, March 20, 2019, https://www.france24.com/en/20190320-focus-crimea-sevastopol-port-naval-base-russia-navy-syria-war-operations-trade-tartus (accessed April 14, 2021).”>REF

It is worth pointing out that Crimea is not the only Russian occupation along the shores of the Black Sea. Since Russia’s invasion of Georgia in 2008, Moscow has maintained a large military presence in the Georgian region of Abkhazia–estimated to be around 4,000 troopsGiorgi Menabde, “Russia Declares New Initiatives to Modernize Army of Breakaway Abkhazia,” Eurasia Daily Monitor, Vol.

16, No.

131 (September 25, 2019), https://jamestown.org/program/russia-declares-new-initiatives-to-modernize-army-of-breakaway-abkhazia/ (accessed April 19, 2021).

“>REF–which has hundreds of miles of coastline on the Black Sea.

Black Sea Operational Challenges

Russia’s A2/AD capability is not the only thing that makes operating in the Black Sea a challenge. Additional diplomatic and political factors complicate the matter.

Passage Restrictions. The 1936 Montreux Convention makes maintaining a robust NATO maritime presence difficult. The convention gave Turkey control over the Turkish Straits and placed limitations on the number, transit time, and tonnage of naval ships from non-Black Sea countries that may use the strait and operate in the Black Sea. Non-Black Sea state individual warships in the Straits must weigh less than 15,000 tons.

No more than nine non-Black Sea state warships, with a total aggregate tonnage of no more than 30,000 tons, may pass at any one time, and they are permitted to stay in the Black Sea for no longer than 21 days.“Montreux Convention Regarding the Regime of the Straits,” July 20, 1936, http://sam.baskent.edu.tr/belge/Montreux_ENG.pdf (accessed April 5, 2021).

“>REF However, it is worth pointing out that the tonnage restrictions do not apply to “naval auxiliary vessels specifically designed for the carriage of fuel, liquid or non-liquid.”Ibid., Art.


For example, in January, the U.S. Navy operated three ships in the Black Sea: the destroyers USS Porter and USS Donald Cook and the replenishment oiler USNS Laramie.Damon Grosvenor, “Second U.S. Destroyer Enters Black Sea, Operates Alongside NATO AIRCOM,” U.S Naval Forces Europe-Africa/U.S.

Sixth Fleet, January 28, 2021, https://www.c6f.navy.mil/Press-Room/News/News-Display/Article/2485628/second-us-destroyer-enters-black-sea-operates-alongside-nato-aircom/ (accessed April 19, 2021).

“>REF The USNS Laramie did not count towards the tonnage allowed by the Montreux Convention. Incidentally, this was “the largest U.S. Navy presence in the Black Sea in three years.”“U.S.

Navy Sends Third Ship into Black Sea, Largest Presence in Three Years,” Radio Free Europe/Radio Liberty, January 29, 2021, https://www.rferl.org/a/u-s-navy-sends-third-ship-into-black-sea-largest-presence-in-three-years/31075511.html (accessed April 5, 2021).”>REF This places limitations on non-Black Sea NATO member operations in the Black Sea region.

Political Challenges. There are also challenges on the political front. Due to internal disagreements among Black Sea NATO members, the Alliance has been unable to meet its expectations in the region. For example, the creation of a permanent NATO maritime force in the Black Sea has been discussed, but not realized. Of the three Black Sea NATO members, Romania is perhaps the most enthusiastic about increasing NATO’s presence in the Black Sea.

On the other hand, Turkey, which has the most capable navy among the Alliance’s Black Sea members, sees the region as more of a national issue and not a NATO one. Therefore Turkey, as the controller and guarantor of the Turkish Straits under the 1936 Montreux Convention, is always cautious, hesitant, and, at times, even suspicious of NATO initiatives for the Black Sea. Finally, Bulgaria is best described as the reluctant partner in the Black Sea.

This is mainly due to domestic political differences about the role NATO should play in the Black Sea. This lack of common understanding by NATO’s Black Sea members makes it more difficult for the Alliance to develop a comprehensive strategy.

Out-of-the-Box Thinking Required

Soon after Russia’s invasion of Ukraine, the U.S., along with several other NATO members, stepped up its presence in the Black Sea. But since then, this presence has been drastically reduced.

Although NATO Secretary General Jens Stoltenberg pledged an increase in NATO ships to the Black Sea in February 2017, progress has not been made as quickly as expected. The restrictions that limit the size, number, and length of stay for non-Black Sea warships in the Black Sea is one of the biggest factors to the reduced presence of NATO in the sea.

An Increased NATO Presence. Obviously, the most immediate solution to this problem is for NATO members to increase their presence by committing to rotational Black Sea patrols: The only thing preventing NATO from doing so is political will. A longer-term solution would be for NATO and its non-Black Sea member states to invest in and help develop the maritime capabilities of the Alliance’s Black Sea littoral states, such as Bulgaria, Romania, and Turkey, along with NATO partners Georgia and Ukraine. However, there are two creative ways to increase the Alliance’s presence in the Black Sea that should be considered:

  1. Germany’s Danube option. According to Article 30 of the 1948 Convention Regarding the Regime of Navigation on the Danube,“Convention Regarding the Regime of Navigation on the Danube,” August 18, 1948, http://www.danubecommission.org/uploads/doc/convention-en.pdf (accessed April 13, 2021).”>REF only Danubian countries may operate naval vessels in the river (or if outside their national borders, then with permission of the relevant Danubian state).Ibid.”>REF Warships of 8,000 tonnes or less can travel 50 miles upriver to Romania’s Port of Braila.

    This would reset the clock on the 21-day limit, allowing Germany to double the time that its warships are allowed in the Black Sea. In 2020, Germany sent one ship, a Frankenthal-class minehunter, displacing 650 tonnes into the Black Sea for a total of 9 days.“British Navy Sandown-Class Minehunter HMS Ramsey M110 Joins NATO Minehunting Force in Baltic,” Naval Maritime Defense Industry, May 30, 2020, https://www.navyrecognition.com/index.php/news/defence-news/2020/may-2020/8501-british-navy-sandown-class-minehunter-hms-ramsey-m110-joins-nato-minehunting-force-in-baltic.html (accessed April 5, 2021).”>REF

  2. The Danube-Black Sea Canal option. This man-made canal in Romania might offer an opportunity for non-Danubian states to reset the clock on the 21-day limit. It is relatively small at 90 meters wide, and can only hold a ship of 5,000 tonnes or less.

    Still, in 2020, a total of 11 naval vessels from Canada, France, Greece, Italy, Spain, the U.K., and the U.S. entered the Black Sea in ships that could, in theory, operate in the canal.

One might reasonably ask about the feasibility of placing a very expensive warship into a narrow canal or river. There are three reasons why this is not an issue.

  1. Any ship entering the Black Sea must travel through a very narrow body of water anyway. At its narrowest point, the Bosphorus Strait is 700 meters wide.

    This strait is also very congested, with civilian maritime traffic reducing maneuverability even more.

  2. Ships using the Bosphorus Strait are prohibited from launching aircraft while transiting. This makes air defense and other force protection measures that are routine when a warship transits through a narrow body of water more difficult. This would not be a problem on the Danube River or the Danube-Black Sea Canal.
  3. The Danube River or the canal would only be used during peacetime.

    After all, during a time of war, Turkey could exert even more control over the entry and exit of the Black Sea.

Importance of Sea of Azov

The Sea of Azov is a small body of water surrounded by Russia and Ukraine and connected to the Black Sea by the Kerch Strait. In the broader discussion about security in the Black Sea, the Sea of Azov is often an afterthought. However, the security of both seas is intertwined, and the U.S. and NATO cannot operate in one without considering the implications and security situation in the other.

The Sea of Azov is relatively shallow and has proven to be strategically important for centuries. In recent years it has been the location of Ukrainian-Russian tensions. In November 2018, a Russian tanker blocked three Ukrainian navy ships’ passage through international waters near the Kerch Strait, and Russian warships opened fire on them, injuring six sailors.

Russian forces boarded the three naval ships, seizing the ships and 24 Ukrainian sailors. It was not until September 2019 that the sailors were finally returned to Ukraine along with the ships. But only after Russia stripped the insides of the ships to make them inoperable.

U.S. Leadership Needed to Improve Maritime Security in the Black Sea and the Sea of Azov Today, the Sea of Azov is important for three geopolitical reasons. 1.

Ukraine’s Economic and Military Well-being. Along the coastline lies Mariupol, Ukraine’s 10th-largest city and one of the country’s leading trade ports. Mariupol is also near the frontlines of the fighting in the Donbas. Under the 2003 Treaty Between the Russian Federation and Ukraine on Cooperation in the Use of the Sea of Azov and the Kerch Strait,“Treaty Between the Russian Federation and Ukraine on Cooperation in the Use of the Sea of Azov and the Kerch Strait,” December 24, 2003, https://www.informea.org/en/treaties/agreement-between-russian-federation-and-ukraine-cooperation-use-sea-azov-and-strait-kerch (accessed April 19, 2021).

“>REF both the Sea of Azov and Kerch Strait are shared territorial waters between Russia and Ukraine.

However, Russia illegally delays Ukrainian commercial ships from passing through the Kerch Strait.Vlagyiszlav Makszimov, “Crimean Experts Warn Russia Has Appetite for Black Sea, More Ukrainian Land,” Euractiv, February 26, 2020, https://www.euractiv.com/section/europe-s-east/news/crimean-experts-warn-russia-has-appetite-for-black-sea-more-ukrainian-land/ (accessed April 14, 2021).”>REF Considering the importance of the strait for Ukraine’s sea-based exports, the economic impact of Russia’s actions is expected to be severe.

2. Russia’s Continued Occupation of Crimea. With Ukraine still controlling access to the Isthmus of Perekop, the Sea of Azov and the Kerch Strait play a role in connecting mainland Russia with Crimea and allow the resupply of Russian troops based there. This is nothing new for Russia.

In fact, throughout the military history of the region, the Sea of Azov has played an important role for resupplying troops on Crimea. In a U.K. House of Lords debate during the Crimean War in 1855, one speaker noted “that considerable quantities, both of grain and iron, had left the Russian ports in the Sea of Azoff (sic) since the commencement of the present war, and that, in fact, the provisioning of the Russian army in the Crimea had been principally conducted from the ports of that sea, and by means of vessels navigating it.”“Blockade of the Sea of Azoff–Question,” U.K.

Parliament, March 1, 1855, https://api.parliament.uk/historic-hansard/lords/1855/mar/01/blockade-of-the-sea-of-azoff-question (accessed April 5, 2021).


In May 2018, Russia inaugurated the first portion of a £7.5 billion, 11.8-mile bridge connecting Russia with Kerch in occupied Crimea. The project will be fully completed in 2023.Neil MacFarquhar, “Putin Opens Bridge to Crimea, Cementing Russia’s Hold on Neighbor,” New York Times, May 15, 2018, https://www.nytimes.com/2018/05/15/world/europe/putin-russia-crimea-bridge.html (accessed April 14, 2021).

“>REF The effect on Ukraine’s regional economic interests can be seen in the fact that 30 percent of the cargo ships that served Mariupol could not clear the span.“Shipping Volumes at Mariupol Port Fall 10 Percent Against 2017: Media,” UNIAN Information Agency, January 9, 2019, https://www.unian.info/economics/10402497-shipping-volumes-at-mariupol-port-fall-10-against-2017-media.html (accessed April 14, 2021).”>REF In December 2019, Russia completed a new rail bridge over the Kerch Strait that the EU condemned as “yet another step toward a forced integration of the illegally annexed peninsula.”Ann M. Simmons, “New Rail Bridge to Crimea Strengthens Russia’s Hand Against Ukraine,” Wall Street Journal, updated December 26, 2019, https://www.wsj.com/articles/new-rail-bridge-to-crimea-strengthens-russias-hand-against-ukraine-11577379297 (accessed April 14, 2021).”>REF


Russia’s Eurasian Identity. Russia’s desire to maximize influence in Eurasia can also help explain, at least in part, its determination to occupy Crimea, dominate the Black Sea, and fully control the Sea of Azov. One of the two canals connecting the Caspian Sea to the outside world is the Volga-Don Canal, which links the Caspian Sea with the Sea of Azov. Russia has used the Volga-Don CanalInterestingly, the U.S. has also used the Volga-Don Canal in the past.

Between 2000 and 2003, the U.S. Coast Guard gave three cutters to Azerbaijan. These ships traveled from the West Coast of the U.S. to Azerbaijan via the Black Sea, Sea of Azov, and the Volga-Don canal to the Caspian Sea.

Obviously, a similar feat would be made impossible today due to the current geopolitical situation.

“>REF to move warships between the Caspian Sea and the Sea of Azov.Paul Goble, “Volga-Don Canal, Last Great Stalin Project, Desperately Needs Updating or Replacement,” Eurasia Daily Monitor, Vol.

17, No.

116 (August 6, 2020), https://jamestown.org/program/volga-don-canal-last-great-stalin-project-desperately-needs-updating-or-replacement/ (accessed April 14, 2021)”>REF

The most recent example is in April 2021, when Russia deployed 15 ships from its Caspian Flotilla to the Sea of Azov as part of its military buildup along Ukraine’s borders.“Moscow Moving 15 Warships from Caspian Sea to Waters off Ukraine.”

“>REF The ability to move warships from the Caspian region, which includes Central Asia, to the Black Sea (and vice versa) allows Russia to project power in an important area of the world, while giving Russian policymakers flexibility and options when a crisis arises in the region. There is also a proposal to create a Eurasia Canal, which would transform the Kuma-Manych Canal (currently only an irrigation canal) into a shipping canal that would link the Caspian Sea and Black Sea. If realized, this would be the shortest route from the Caspian Sea to the outside world.

FONOPs and the Sea of Azov

A Freedom of Navigation Operation (FONOP) is a legal mechanism used to document the U.S. non-recognition of specific excessive maritime claims.

The U.S. has carried out FONOPs since 1979, using military forces, notably the Navy, in consultation with Department of State and U.S. diplomats in the target country. To document its legal non-recognition of specific claims, the Department of Defense publishes the claims it has contested using FONOPs in an annual report to Congress.U.S. Department of Defense, “DoD Annual Freedom of Navigation (FON) Reports,” https://policy.defense.gov/ousdp-offices/fon/ (accessed April 5, 2021).


Some called for a U.S.-led FONOP to happen soon after the 2018 Kerch Strait incident, but due to the then-geopolitical circumstances, it was neither realistic nor advisable for the U.S. to send warships into the Sea of Azov.

Almost three years after the incident, a FONOP done under the right circumstances would be right and proper. Legal Obstacles. However, there are legal obstacles currently in place that would make this easier said than done. For example, according to a 2003 Treaty on the Legal Status of the Sea of Azov and the Kerch Strait, both the Sea of Azov and Kerch Strait are shared territorial waters between Russia and Ukraine.

Section 3 of the treaty states that both parties have to consent to any foreign warship or other state ship entering the Sea of Azov. Obviously, Russia would not agree to a U.S. or NATO warship doing so. Even with Russia’s aggression and an illegal occupation of Crimea, Ukraine still remains a party to the 2003 agreement for reasons that seem based on the pretext it might bolster arbitration with Russia; a position that seemingly is a legal fiction given recent hard power realities in Crimea and eastern Ukraine.

Also, the Department of State has never issued a Limits of the Seas report on this strait. The Department of State’s Office of Ocean and Polar Affairs’ Bureau of Oceans and International Environmental and Scientific Affairs conducts legal reviews of coastal states’ maritime claims to assess consistency with international law. The last report done on a great power competitor was in December 2014 (regarding China’s Nine Dash Line in the South China Sea)–and no report has ever been done on the Kerch Strait, let alone Black Sea excessive claims.

In this case, it is important that the U.S. submits a report on the Kerch Strait to clarify U.S. legal understandings of this waterway and form a basis for any follow-on actions. Consequently, before the U.S. or its allies can conduct a FONOP through the Kerch Strait and into the Sea of Azov two things must first be done. First, Ukraine needs to announce that it no longer considers itself bound by, or a party to, the 2003 Treaty on the Legal Status of the Sea of Azov and the Kerch Strait.

Second, the U.S. State Department needs to issue a Limits of the Seas report on the Kerch Strait. At this point, if U.S. policymakers want to seriously consider a FONOP, there are at least four possible options to consider:

  • Option 1: A FONOP with a U.S.

    Navy warship. The U.S. Navy could conduct a FONOP transiting the Kerch Strait similar to the way it conducts other FONOPs throughout the world. This would carry high risk and could be a stand-alone mission or part of a U.S.-Ukraine bilateral maritime exercise.

    The U.S. would have to be mindful of the Montreux Convention’s restrictions.

  • Option 2: A FONOP conducted by a Black Sea NATO member with U.S. support. Another option is for Bulgaria, Romania, or Turkey to conduct a FONOP transiting the Kerch Strait with the United States providing supporting capabilities, such as a P-8 Poseidon. This option would be considered less controversial than Option 1 because the FONOP would be carried out by a Black Sea nation.

    However, there is no record of any Bulgarian, Romanian, or Turkish warships entering the Sea of Azov in recent memory. Again, this could be done as a stand-alone mission or as part of a NATO-Ukraine maritime exercise.

  • Option 3: A FONOP with a Military Sealift Command ship. Military Sealift Command (MSC) operates more than 100 non-combatant, civilian-crewed ships that support U.S. Navy ships.

    These ships are generally unarmed and used for resupplying other ships. Certain supply ships have fewer restrictions under the Montreux Convention. Like Option 2, this could be a less provocative course of action compared to Option 1.

  • Option 4: A FONOP with a U.S.

    Coast Guard ship. Conducting a FONOP with a U.S. Coast Guard ship would be similar to Option 1, but seen as less confrontational since it would not be the U.S. Navy conducting the operation.

    Although the U.S. Coast Guard has operated in the Black Sea before, it must be noted that restrictions under the Montreux Convention still apply.


The economic, security, and political importance of the Black Sea and the Sea of Azov is only becoming more important. With Russia increasing its military capability in the region, now is not the time for the U.S. or NATO to grow complacent.

The U.S. and NATO must increase their presence in both seas. This can be done by:

  • Developing a maritime strategy that includes both the Black Sea and Sea of Azov regions. The U.S. should be a leader inside NATO to develop meaningful ways for working with the littoral states to develop a strategy for regional security. Since Russia’s annexation of Crimea, the Sea of Azov has essentially become a Russian lake–but the Black Sea is contested like never before in modern history.

    This is a direct threat to U.S., NATO, Ukrainian, and Georgian security interests. Many of the recent initiatives at the NATO level have not met expectations.

  • Working with NATO to establish a Black Sea Maritime Patrol mission modeled on the Baltic Air Policing mission. NATO’s interest in Black Sea security is increasing, but the overall presence of non-Black Sea NATO warships is decreasing. NATO should establish a Black Sea Maritime Patrol mission modeled on the successful Baltic Air Policing mission in order to maintain a robust NATO presence in the Black Sea in line with the 1936 Montreux Convention.

    This would require non-Black Sea NATO countries to commit in advance to a regular and rotational maritime presence in the Black Sea.

  • Supplying more ships to Ukraine. A strong Ukrainian Navy is in America’s interest. After years of delay, the U.S. finally transferred two Island-class former Coast Guard ships to Ukraine. Three more Island-class ships for Ukraine are planned.

    This is a good first step in rebuilding Ukrainian maritime capability. The U.S. should accelerate providing inactivated warships, such as recently retired Cyclone-class patrol ships through the Excess Defense Articles program.Richard R. Burgess, “Navy Begins Retirement of Cyclone-Class Patrol Ships Without Replacement,” Seapower Magazine, February 19, 2021, https://seapowermagazine.org/navy-begins-retirement-of-cyclone-class-patrol-ships-without-replacement/#:~:text=The%20three%20PCs%20being%20retired,%2C%20Zephyr%20and%20Tornado%2C%20respectively (accessed April 2, 2021).”>REF

  • Helping Ukraine improve its maritime capabilities. The right to self-defense does not stop at the shoreline.

    The U.S. can help fund and speed up research to get Ukraine’s domestically produced Neptune anti-ship missile in operation faster. In addition, the U.S. should consider appropriate and ready options for anti-ship missile platforms for Ukraine. The U.S. should also help to improve Ukraine’s maritime security by providing improved radar and appropriate surveillance capabilities, such as unmanned aerial vehicles.

  • Helping Georgia improve its maritime capabilities. After Russia’s invasion of Georgia in 2008, the Georgian Navy was all but destroyed.

    Since then, Georgia has built a Coast Guard that falls under the authority of the ministry for internal affairs. In the past, the United States has gifted former U.S. Coast Guard ships to Georgia.

    While Georgia’s maritime aspirations remain limited, the U.S. should work closely with Tbilisi to find maritime security issues.

  • Opening a NATO-certified Center of Excellence on Black Sea Security in Georgia. There is no precedent for a NATO-certified Center of Excellence in a non-NATO country, but establishing one could improve NATO-Georgia relations and show how important the Black Sea region has become for Europe’s overall security. The Center of Excellence would provide an opportunity to engage in meaningful dialogue and training in how to address the challenges associated with Black Sea security.
  • Thinking creatively about increasing Alliance presence in the Black Sea. In addition to establishing a Black Sea Maritime Patrol, NATO needs to explore more unconventional proposals to increase the length of time for which non-Black Sea countries operate in the sea. This should include the possible use of the Danube River or the Danube-Black Sea Canal.
  • Working with Romania to carry out a feasibility study on the Danube-Black Sea Canal. This man-made canal in Romania might offer an opportunity for non-Danubian states to reset the clock on the 21-day limit.

    It is relatively small at 90 meters wide, and can only hold a ship of 5,000 tonnes or less. The U.S., NATO, and Romania should conduct a study to see if using the canal would be possible from both a practical and legal perspective to extend the length of time a non-Black Sea country can keep a ship in the sea.

  • Conducting a Limits of the Seas report on the Kerch Strait. The U.S. Department of State’s Office of Ocean and Polar Affairs’ Bureau of Oceans and International Environmental and Scientific Affairs conducts legal reviews of coastal states’ maritime claims to assess consistency with international law.

    The last report on a competitor nation was published in December 2014 (regarding China’s Nine Dash Line in the South China Sea)–and no report has ever been published on the Kerch Strait, let alone Black Sea excessive claims.

  • Consulting with European partners about the OSCE establishing a maritime monitoring mission in the Sea of Azov. Currently, OSCE monitors only operate on land in eastern Ukraine. The OSCE should consider expanding this mission to the Sea of Azov to ensure that all parties in the region live up to their legal commitments and obligations.
  • Improving situational awareness of the maritime situation in the Sea of Azov. The Commander of the U.S. Navy Sixth Fleet, Vice Admiral Eugene H.

    Black III, should pay a visit to Mariupol. A visit by America’s top naval commander in Europe would help to get an enhanced understanding of the security situation on the ground, as well as a better sense of Ukraine’s maritime requirements. This would better inform U.S. policy.

  • Making sure Turkey is involved. Any proposals to increase U.S. presence in the Black Sea should include involvement and consultation with Turkey.

    Turkey is a NATO member with sovereign control of the straits. It should be explained to Ankara that nothing the U.S. or NATO does in the Black Sea is meant to undermine this control. The goal is to increase NATO’s presence in the Black Sea to deter and, if required, defeat Russian aggression.

  • Ensuring NATO’s door remains open for Georgia and Ukraine. These are two Black Sea countries that know what it is like to suffer from Russian aggression.

    They also aspire to join the Alliance someday. Without close cooperation and relations with both, NATO cannot have an effective Black Sea/Sea of Azov strategy. Also, as long as they aspire to join the Alliance, the U.S. should help them along the way.

    No non-NATO country, such as Russia, should have a veto on their future potential membership.


The economic, security, and political importance of the Black Sea and the broader region is becoming more important. Security in the Sea of Azov is closely connected to security in the Black Sea. The security of the Black Sea is important not only for NATO’s southern flank, but also to keeping the door open for future NATO membership for Ukraine and Georgia.

With Russia using the Black Sea as a springboard for operations in places like Syria and Libya, and with continued Russian aggression against Ukraine and Georgia, the U.S. and the Alliance cannot ignore the region.

Luke Coffey is Director of the Douglas and Sarah Allison Center for Foreign Policy, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation. Brent Sadler is Senior Fellow for Naval Warfare and Advanced Technology in the Center for National Defense, of the Davis Institute.

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