The Black Sea’s present and future are tied up with the progression and outcome of Russia’s war of aggression in Ukraine. The world at large has an essential stake in the Black Sea’s freedom. Its security is simply too important to be left to the vagaries of the Ukrainian conflict. The free Black Sea nations should lead the effort to articulate and execute—in collaboration with their allies and partners—a free and open Black Sea compact to preserve its independence. The United States, EU, and NATO, in their own interests, should commit unwavering support and resources to ensure the compact’s success.

A free and open Black Sea is a lifeline to peace and prosperity for South-Eastern Europe, the Caucasus, and Central Asia. Black Sea inaccessibility has wide-ranging ramifications beyond the region, as demonstrated by the global food and fertilizer shortages and price hikes since 2022—particularly in Africa and the Global South. Black Sea, in addition to being critical to global agriculture, also serves as a main conduit for Europe-Asia oil and gas pipelines, fiber-optic cables for data and telecommunication, proposed renewable energy power lines, and a prospective outlet for Central Asian mineral resources. The Black Sea represents the sole maritime access for NATO and EU members Bulgaria and Romania, as well as Georgia and Ukraine.

An unfree Black Sea threatens NATO’s eastern front and undermines transatlantic and regional economic and security interests. Consequently, it behooves the United States and Europe to act in close concert with the region’s coastal states to ensure the accessibility of this geostrategic water body. 

The Black Sea, from the classical Greek age, has been a strategic roundabout for transcontinental commerce and cultural exchange. Consequently, its control was contested over the centuries by the Greeks, Persians, Romans, Huns, Byzantines, Ottomans, Russians, and so on. The Ottomans and Russians, in particular, fought numerous wars over four centuries for hegemony over the Black Sea and Crimea. 

The post-Soviet era paved the way for the integration of the Black Sea nations into the free world and facilitated their transition to market economies. An imperialist Russia is acting to reverse these gains. Russia’s malign intent and unlawful annexation of the Georgian Abkhazia and Tskhinvalki regions in 2008, Ukrainian Crimea in 2014, and Donetsk, Kherson, Luhansk, and Zaporizhzhia in 2022 are directed at usurping the Black Sea to the detriment of the littoral states, Transatlantic interests, and the global community. 

Undeterred Russian aggression will render the region a persistent ulcer of war and conflict. A coordinated and resolute deterrence is needed to arrest and reverse the present trend. A collective compact to protect the Black Sea and propel commerce and connectivity between Asia and Europe and between the Black and Mediterranean Seas is needed. 

Littoral nations with the most at stake should collectively lead the charge. In January 2024, Romania, Bulgaria, and Turkey agreed to coordinate the clearing of floating mines from their collective EEZs (exclusive economic zones). They established a four-vessel task force with a national mine-clearing ship from each country and one additional command coordinating vessel. The three nations also share a substantial interest in developing their respective Black Sea natural gas reserves. It stands to reason that the three share an interest in building on their burgeoning coordination. 

Romania, where Europe’s second longest river, the Danube, enters the Black Sea, is a stable European and NATO anchor in the region. By 2027, it is projected to become Europe’s largest natural gas producer. Turkey straddles the Bosporus and Dardanelles Straits, the narrows connecting the Black Sea to the Mediterranean. The 1936 Montreux Convention grants Turkey uncommon control over the size and types of vessels crossing the straits. Bulgaria, situated between Romania and Turkey, depends on the Black Sea for its economic growth, particularly in terms of energy, minerals, transportation, and tourism. Consequently, Sofia has increased attention to Black Sea security, including investments in military infrastructure and meeting NATO’s 2 percent target. Moldova, landlocked and the most vulnerable to Russian aggression among the regional states, can access the Black Sea through its Danube River port—Giurgiulesti. 

Turkey, with the weight of history and geography, is both most obligated to push for a free and open Black Sea compact and the most likely to benefit from it. Russia’s unlawful and unchecked expansion of its EEZ through the annexations of Georgian and Ukrainian coastlines is detrimental to Turkish plans for becoming the leading bridge nation among the fast-converging Asian, European, and Middle Eastern economies. As the largest NATO nation on the Black Sea, it bears additional responsibility to advance the collective security interests of existing and prospective NATO members adjoining the water body. 

Romania and Bulgaria—in close cooperation with the United States, EU, and NATO—have embarked on ambitious defense modernization efforts. An investment of $2.7 billion is set to transform Romania’s Mihail Kogălniceanu Air Base into one of the largest in Europe. The two nations are also cooperating with Washington to diversify and modernize their nuclear energy infrastructure, including the use of small modular reactors. 

Romania, Turkey, and Bulgaria should build on their mine-clearing cooperation to develop a framework for a free and open Black Sea along three reinforcing pillars. First, the states should articulate a shared vision, including the recognition of the pre-2008 Russian EEZ. Second, they should establish modalities and taskforces as appropriate for the security of 1) critical infrastructure associated with energy exploration and development; 2) digital cables at risk from cyber-attacks; 3) proposed power lines connecting Azeri wind farms and Georgian hydropower to Europe; 4) third-party commercial vessels from attacks or harassments. Third, they should optimize the commercial transit capabilities of rivers flowing into the Black Sea—particularly of the Danube.

In developing the framework for a free and open Black Sea, the three nations may prudently solicit perspectives and participation of like-minded neighbors, including Georgia, Moldova, and Ukraine. Pragmatism points to cementing tripartite collaboration and coordination in the western Black Sea and reaching out to like-minded neighbors. As NATO members, Bulgaria, Romania, and Turkey should also develop modalities for engaging with the alliance as a whole to back their efforts in the Black Sea. 

The United States, European Union, and NATO should commit to efforts that would bolster the littoral states’ abilities to sustain a free and open Black Sea. First, they should help build the naval capabilities of littoral NATO members and prioritize the modernization of the Romanian and Bulgarian navies, with attention to developing Constanța as the premier NATO naval port in the region. Second, the region needs better road, rail, and river infrastructure to integrate into Europe and aid defense mobilization and readiness. Third, the Black Sea compact should be incorporated within strategic planning documents, including the U.S. Black Sea Strategy, the EU’s Strategic Compass, and NATO’s Strategic Concept. Notably, the United States should assign the Black Sea a frontline role in linking the free and open spaces across the globe from the Indo-Pacific to the Mediterranean and Atlantic.  

The driving rationale for the Montreux Convention was to preserve the balance in the Black Sea. Russia’s illegitimate imperialist annexations are imperiling that balance. Across the world, a preference for regional multipolarity and free, open, and shared access rather than a single nation’s dominance is taking hold. These two trends call for a modern approach to advance the principles of balance underlying the Montreux Convention through a compact for a Free and Open Black Sea.

Kaush Arha is president of the Free & Open Indo-Pacific Forum and a nonresident senior fellow at the Atlantic Council and the Krach Institute for Tech Diplomacy at Purdue.

George Scutaru is the CEO of the New Strategy Center and a former national security advisor to the President of Romania. 

Yordan Bozhilov is the President of the Sofia Security Forum and a former Deputy Minister of Defense of Bulgaria. 

Mamuka Tsereteli, President of America-Georgia Business Council, Senior Fellow for Eurasia and Central Asia at the American Foreign Policy Institute.

Image: Shutterstock.com.