Constanța blast exposes NATO’s maritime drone gap

At 06:00 on June 5, Romanian forces detected a Ukrainian naval drone inside the civilian port of Constanța, NATO's largest Black Sea logistics hub. Four hours passed. At 10:00, Ukraine warned Romania it had lost control of four drones to Russian electronic warfare jamming. At 10:28, the drone self-detonated at berth 78, five hundred metres from an oil terminal (Agerpres, Straits Times). Nobody died. But the four-hour gap between detection and notification mattered more than the blast. No protocol for armed drones entering a civilian port existed.

This was the second incident in a month. On May 7, fishermen found a Ukrainian drone carrying explosives in a sea cave off Lefkada, Greece, its engine still running (skai.gr). Ukraine blamed Russian electronic warfare for the loss of control both times (Maritime Executive).

Built for Ships, Blind to Drones

Romania's coastal surveillance system, SCOMAR, tracks vessels larger than six metres. Ukrainian Sea Baby drones measure roughly five. The Interior Ministry acknowledged that small platforms with low radar signatures "were not among the objectives for which the system was originally designed." The port's recently installed counter-drone system covers airspace, not the water surface (HotNews).

Jurisdiction is equally fragmented. Defence Minister Radu Miruță said the military does not guard civilian ports. The coastguard monitors traffic. The port authority manages the site. Four institutions share responsibility for Constanța, and none had a plan for armed drones entering the harbour.

Romania's path to closing the detection gap is blocked by its own politics. The country's multibillion-euro SAFE defence procurement programme, designed in part to address low-altitude and surface surveillance gaps, is stalled by a constitutional court challenge filed by members of the same governing coalition that approved it. Until that is resolved, NATO's largest Black Sea port depends on sensors built for cargo ships.

Bulgaria, which shares the coastline, activated radar and helicopter patrols within hours. Its surveillance faces the same basic limitation: systems calibrated for conventional vessels, not five-metre drones with minimal radar signatures (armymedia.bg).

A Security Hub That Exists Only on Paper

The EU's proposed response is a Black Sea Maritime Security Hub. It has no legal basis, no budget, and no host city, originating from a 2025 Joint Communication (a policy paper with no binding force) (EEAS). Romanian MEP Victor Negrescu has called for accelerating it as a direct consequence of the Constanța explosion, but acceleration means little when the starting point is a concept document.

A leaked EU Council document from May 2026 confirmed that each country still treats drone security as its own problem, with member states operating "in silos" and no shared detection or response system (Euronews). The EU's counter-drone action plan, adopted in February 2026, commits to a maritime awareness "pilot action," with full deployment not expected before 2030 (Counter-UAS Action Plan). Even that plan focuses overwhelmingly on aerial threats. Surface naval drones barely feature.

A Treaty Designed for a Different Kind of Ship

The 1936 Montreux Convention, which governs naval passage through the Turkish Straits connecting the Black Sea to the Mediterranean, classifies vessels as either merchant or military. Naval drones fit neither category. They carry no crew, no commissioned officer, and Ukraine has not registered them as warships (Opinio Juris). Turkey has neutralised at least 11 stray drones in its waters but has said nothing about their legal status under the convention (Daily Sabah). That silence serves Ankara. Raising the question would force it to either restrict Ukrainian drones or formalise their right of passage.

The Constanța drone hit a breakwater, not a tanker. Romania has since asked Ukraine to notify it whenever control of a weapon is lost. That bilateral request is all Europe has right now. One country asking the drone operator to phone ahead when something goes wrong, while the ports stay exposed and no legal framework acknowledges these weapons exist.