Deepening Black Sea Crisis Demands US Involvement

Something very serious is happening in the Black Sea, and it demands a response. Merchant ships are being attacked and sunk without warning in the latest, highly provocative action in Russia’s shadow war against European NATO members. A slew of drone attacks on merchant vessels off the coasts of Romania and Bulgaria, attributed to Russia, have killed at least two sailors and left 13 missing. On October 5, a Turkish cargo ship hit by drones sank in Romania’s exclusive economic zone. Two crew members died, and rescuers managed to save another 11. The following week, two chemical tankers were set ablaze, one just inside and one just outside Romanian territorial waters. A total of 21 are thought to be missing. Some of the vessels were engaged in trade with Ukraine, but several were not, suggesting that the Kremlin’s attacks served a wider and more worrying purpose. Bulgaria has now asked NATO for the deployment of combat aircraft and anti-drone systems to its territory. “We have sent letters and a request to the NATO Secretary General and the Supreme Allied Commander, urging them to strengthen our capabilities, which also means deploying additional forces on our territory. We are awaiting their decision,” Defense Minister Dimitar Stoyanov said on October 16. On October 18, France sent a maritime reconnaissance aircraft to Romania. The attacks, which NATO said were carried out by Russia, were the latest in a pattern of increasingly destructive Russian shadow warfare on the alliance’s southern doorstep. And it’s not just shipping. In August, a Romanian F-16 destroyed an explosive-laden sea drone a few meters from the platform at the heart of the Neptune Deep gas project. Romania’s President Nicușor Dan blamed Moscow. A week later, a merchant ship was hit and sank in the same waters. The threat to Romania is much wider. Next year, the giant Neptune Deep gas field is due to start production. It has some 100 billion cubic meters of recoverable gas and is a cornerstone of Europe’s effort to wean itself off Russian hydrocarbons. As Romania’s Chief of Defense General Gheorghiță Vlad has acknowledged, the offshore infrastructure isn’t protected by NATO’s collective defense guarantees because it is in Romania’s exclusive economic zone but not in its territorial waters. The crisis comes at an awkward moment for the West, as Washington considers how much of the alliance’s southern flank it still wants to invest in protecting. The US remains overwhelmingly the alliance’s biggest military power, and might in earlier times have been expected to lead a reinforcement effort, along with political support for exposed allies. But the American military footprint in Romania is already considerably smaller than it was at the start of President Donald Trump’s administration. In October 2025, the Pentagon chose not to replace the rotational brigade there, effectively withdrawing about 800 troops, mostly from Mihail Kogălniceanu (MK) Air Base. Ironically, this has been a base Washington has used since earlier this year for refueling aircraft to strike Iran. Unlike other European countries, which denied or conditioned access to military bases for Operation Epic Fury, Bucharest didn’t wait for Washington to ring twice and greenlight the request the same day. The Republican chairmen of both congressional military committees, Senator Roger Wicker and Representative Mike Rogers, publicly objected to the withdrawal from MK at the time, warning it could create a deterrence gap in a vulnerable region. Romania’s case inspired a bipartisan provision in the 2026 National Defense Authorization Act, which bars the Pentagon from reducing US forces in Europe below 76,000 personnel without meeting strict congressional notification and certification requirements. Elbridge Colby, who, as Pentagon policy chief, is overseeing the main force posture review, has long argued that America must prioritize deterring China, and Europe must carry more of its own defense. But prioritization done right means cutting where the risk is lowest, and the US presence in the Black Sea is among the highest-return investments America has in Europe. The case is strong for a sustained American presence in the Black Sea. First, MK is not only a European asset, but, as shown during operations against Iran, is vital for American power projection in the Middle East. It hosted tankers, intelligence and surveillance aircraft, along with additional personnel. Such fast and flexible access from a loyal ally is exactly what a stretched American military needs. Second, Romania is already doing what the Pentagon asks of allies by spending more than €2.5bn ($2.8bn) to turn MK into one of NATO’s largest bases. Romania also joined the F-35 program, investing $6.5bn for the fifth-generation aircraft. Cutting US capacity in Romania would punish the kind of ally the administration says it wants in Europe and discourage others from following its example. Third, the presence is cheap for what it buys. It gives Washington eyes on Russia’s Black Sea Fleet and China’s Belt and Road investments, reassurance to a stalwart frontline ally, and a credible stake in protecting the energy infrastructure Europe needs to replace Russian gas. At a minimum, the posture review should preserve what remains at MK, including the much-needed air combat group, which Romania’s defense ministry said would stay after the 2025 withdrawal. Ideally, Washington should consider adding rotational assets matched to the threat now visible in Romanian waters, such as maritime patrol aircraft, counter-drone systems, and air defense capable of covering offshore platforms. While other countries, like Turkey or France, might become engaged, a credible American anchor needs to remain. The US is likely to reduce its footprint in Europe, but it should do so in a manner that allows Europe to step in seamlessly. The Pentagon should also recognize the Black Sea as a hotspot where Russia is testing NATO’s resolve, with drones, sunken ships, and dead sailors. A sustained US air and surveillance presence at MK is a small price to pay for stopping the Kremlin’s provocations from becoming an even more costly crisis. Mark Montgomery is a retired U.S. Navy rear admiral and a senior fellow at the Foundation for Defense of Democracies. He was formerly a policy director for the Senate Armed Services Committee. Antonia-Laura Pup is a doctoral researcher at the European University Institute. She previously served as a fellow in the House Select Committee on China in Congress, and as an advisor in the Romanian Parliament.