Bulgaria has formally asked NATO to deploy combat aircraft, missile defences and anti-drone systems on its territory after a succession of attacks on commercial vessels in the Black Sea brought the dangers of the Russia-Ukraine war closer to the alliance's southeastern coastline.
Defence Minister Dimitar Stoyanov confirmed on Friday, October 16, that Sofia had written to NATO Secretary General Mark Rutte and the alliance's Supreme Allied Commander Europe requesting additional military support. The government is seeking fighter aircraft, surface-to-air missile systems, maritime patrol aircraft and equipment capable of detecting and intercepting drones. NATO has yet to decide what assistance it will provide.
The request follows another difficult week for Black Sea shipping. Two vessels caught fire after drone strikes near Romania's coast, while a commercial ship sank off Bulgaria on October 13. Sofia subsequently summoned Russia's ambassador, although investigators have not conclusively established responsibility for the attacks.
Bulgarian authorities had already been investigating drone strikes against two merchant ships in the country's Black Sea economic zone earlier this month. One vessel sank, while another caught fire and required a rescue operation. The incidents have left Sofia confronting a security problem that extends well beyond protecting its ports.
On October 12, the Bulgarian government requested technical assistance from NATO and the European Union to investigate the attacks. Prime Minister Rumen Radev sought support from European Council President António Costa, European Commission President Ursula von der Leyen and NATO's secretary general.
The latest appeal goes further, seeking military equipment and allied forces rather than investigative assistance alone.
Bulgaria's predicament is complicated by geography and international maritime law. Its exclusive economic zone extends beyond territorial waters, giving the country certain rights over resources without making those waters sovereign Bulgarian territory. Attacks on foreign-flagged vessels there do not automatically trigger NATO's collective-defence obligations, even when they threaten shipping routes essential to regional trade.
Romania faces many of the same pressures. Stoyanov plans to meet his Romanian and Turkish counterparts to discuss a coordinated approach to maritime security. The three countries already cooperate on clearing mines from the Black Sea, but the growing threat from aerial drones requires different surveillance and interception capabilities.
NATO has spent the past year expanding its response to drone incursions along its eastern frontier. In September, an unidentified drone was shot down over Lithuania, illustrating the pressure on allied air defences far from the Black Sea. The alliance's Eastern Sentry mission and counter-drone measures were developed to improve surveillance, coordination and interception across the eastern flank.
Bulgaria expects to join a NATO counter-drone initiative by the end of October. It has also proposed a moratorium on attacks against civilian shipping in the Black Sea.
For Sofia, the immediate uncertainty concerns the scale and timing of allied assistance. Other NATO members, including Romania and the Baltic states, are seeking similar capabilities, and the alliance must balance those requests against existing deployments. Commercial ships, meanwhile, continue operating through waters where an increasingly intensive drone war has made even routine voyages difficult to secure.
