The Ukraine war’s spillover into the Black Sea is creating a growing European security and commercial risk: Drones are hitting ships and killing sailors, grain routes are under strain, and insurers and investors are weighing the cost of operating through Ukraine’s ports.

Five commercial vessels have been hit in Bulgarian and Romanian waters over the past week alone, leaving at least four people dead, several sailors missing and others injured. In response, Black Sea countries Bulgaria, Romania and Turkey have raised the issue at NATO, asking for more focus toward the region and joint support, according to two alliance diplomats.

“The attack within Bulgaria’s exclusive economic zone is absolutely unacceptable. It constitutes a serious breach of maritime and international law and will further jeopardise safe navigation in the Black Sea,” Bulgarian Prime Minister Rumen Radev said on X after the attacks last week.

Russia has been attacking Ukrainian ports and cities in the area since the start of its full-scale invasion. But the recent strikes have brought the spillover into NATO territory. If they continue, EU leaders will face pressure to protect Black Sea shipping and keep Ukrainian trade moving.

Those questions will be top of mind at Thursday’s European Council summit. According to draft conclusions obtained by POLITICO, leaders are expected to discuss the “immediate restoration of safe passage for grain cargo ships.”

A wider problem

Russia is not the only country using naval drones in the Black Sea. Ukraine has also used them against Russian-linked shipping. In June, a Ukrainian sea drone exploded in Romania’s Constanța port after Kyiv said it had veered off course because of Russian electronic interference.

“The Black Sea situation is quite dangerous because attacks are coming from both [sides],” said an EU shipping representative, who was granted anonymity to speak freely. “You have to worry about both.”

Attribution can also be difficult. Bulgarian Prime Minister Rumen Radev said Wednesday that investigators still have not proven that Russia is behind the strikes — although some have attributed his reticence to his broadly softer approach toward the Kremlin.

Drone operations by both Russia and Ukraine are likely to continue as long as each has the money and production capacity to sustain them, said Cristian Vlas, assistant research manager for Eastern Europe at the think tank ACLED.

Oleksii Goncharenko, a Ukrainian lawmaker and founder of the Black Sea Security Forum, told POLITICO that a “serious diplomatic initiative” was needed, bringing together Ukraine, Russia and a third-party guarantor, such as Turkey, “to restore freedom of navigation in the Black Sea.”

Grain routes under pressure

The security risk is disrupting routes that carry Ukraine’s harvest to market, with consequences for EU transport links. Black Sea ports are Ukraine’s main export gateway, handling around 95 percent of the country’s grain exports, as well as significant volumes of iron ore. Shipping traffic has fallen as the security risk has grown.

Some cargo is being rerouted to the River Danube, but capacity there has been stretched in recent months as drought pushes water levels to record lows. Operators are trying to add rail capacity, but that risks moving the bottleneck westward to Romania.

Moving more Ukrainian grain overland also risks reviving tensions with farmers in neighboring EU countries, Vlas said. Romanian farmers have worried that Ukrainian produce meant only to transit could stay on the domestic market, he added, while transport operators are already juggling competing demands for capacity.

Ukraine’s Agriculture Minister Taras Vysotskyi has warned that millions of tons of unsold grain is piling up, and that farmers who can’t sell won’t be able to afford to resow all their land.

Bulgaria is working with Romania and Turkey on a joint initiative to protect freedom of navigation in the Black Sea, which Radev plans to bring to EU leaders on Thursday.

Following the Black Sea countries’ request at NATO, military officials are likely to look into possible options such as shifting counter-drone systems to the region, the two alliance diplomats said. Radev said Sofia will convene his counterparts in Ankara and Bucharest to examine further proposals, while a senior Bulgarian official called for new joint anti-drone systems with Romania, partly financed by the EU.

Investment at risk

The attacks also threaten what had started to look like a renewed bet on Ukraine’s ports. MSC, the world’s largest container line, was among the biggest and newest investors, reportedly acquiring a majority stake in a container terminal at a port near Odesa in May.

Ukraine has also been offering investors a long-term concession at the Chornomorsk terminal near Odesa. This terminal is one of Ukraine’s largest planned port public-private partnerships and part of what is expected to be a multibillion-euro reconstruction effort involving European companies.

But people who work in Ukraine’s ports say the case for rebuilding is collapsing.

“No one is ready to invest and rebuild, since you know that tomorrow there will be another missile, another pack of drones,” Oleg Grygoriuk, chairman of Ukraine’s Marine Transport Workers’ Trade Union, said.

BRUSSELS — The EU will only conduct further releases of oil and diesel reserves after the International Energy Agency has made it clear such a move would not be damaging to the bloc’s energy security, three diplomats familiar with the matter told POLITICO.

The Group of Seven — which includes Italy, Japan, Germany the U.K., France and the U.S. — agreed on Friday to release 100 million barrels of oil and diesel after U.S. officials threatened to ban diesel exports if they didn’t tap stockpiles.

However, the IEA appeared to confirm Wednesday that that release would draw from stocks pledged under an agreement in March and not include additional supplies. In other words, it would not amount to a new release at all, but would simply fulfil prior promises.

In a meeting Wednesday afternoon, EU officials endorsed the position, pledging to defer any future drawdowns “pending a clearer IEA assessment of market conditions and security-of-supply risks,” said one of the diplomats. Countries need to know “how low we can go,” said another.

While diesel prices are high as a result of airstrikes on energy infrastructure in Russia and the Middle East, some EU countries warned that releasing stocks now could leave them vulnerable in the event of a supply crisis.

There remain enough untapped stocks among IEA members to satisfy the pledge to release 100 million barrels.

Of the 400 million barrels pledged in March, 325 million have been released, with some countries releasing “greater volumes than they initially pledged,” the IEA said in a statement following an emergency ministerial meeting. That leaves around 100 million left that countries can still release under that agreement, it added.

It said the fresh commitment would represent a “completion” of that March agreement. The IEA’s 32 members include wealthy European, North American and East Asian countries.

POLITICO reported earlier Wednesday that France and Germany — which hold some of Europe’s most significant stockpiles — had signalled they would release no or minimal supplies on top of those already pledged.

It remains unclear what share of the releases non-EU members of the IEA will accept, after Japan, another member, ruled out any further releases.

Further details on the breakdown of the G7 release will be discussed at a meeting of the IEA’s governing board next week, the second diplomat said.