The Black Sea is Nato's new front line against Russia

Earlier this month, an unarmed Polish aircraft monitoring potential human smuggling and illegal fishing on the Black Sea almost ditched into the sea when a Russian Su-35 fighter engaged it over international waters. It was a reminder that while attention is inevitably focused on the land battles anticipated when Kyiv launches its spring counter-offensive, this is also a war playing out at sea. It was also a reminder that what happens offshore has far wider implications.

The twin-engine L-410 Turbolet, more commonly used as a small commuter aircraft, was being used by Frontex, the European Union’s border security agency, as part of its Western Black Sea 2023 operation. It was a routine flight, and unlike the American MQ-9 Reaper drone downed in March, offered no conceivable threat to Russian forces. Nonetheless, the Su-35 performed what the Romanian defence ministry called ‘aggressive and dangerous’ manoeuvres that almost made it lose control, driving it back to Romania’s Mihail Kogălniceanu Airport.