Ukrainian forces struck a corvette of the Russian Baltic Fleet - and not just anywhere, but at the Kronstadt base near St Petersburg, around 1,100 kilometres from the Ukrainian border. The message is clear: even the deep Russian rear is no longer safe.

The strike on the corvette „Boiky" took place on the night of 2-3 June. Kronstadt, on Kotlin Island in the Gulf of Finland, some thirty kilometres west of St Petersburg, is the historic home of the Baltic Fleet - strategically and symbolically one of the most important Russian naval strongholds. That is exactly why the hit hurts twice over.

It is a Steregushchiy-class corvette (project 20380), at around 2,200 tonnes and 105 metres long, armed with Kh-35U cruise missiles with a range of about 260 kilometres. Not a giant ship, but a modern one - and its damage is a blow to prestige as much as to the fleet.

Ukraine's drone forces and the security service (SBU) confirmed the action. President Zelensky described it as part of a wider operation aimed at „exclusively military targets" in Kronstadt, together with strikes on an oil terminal in St Petersburg and a factory in Tambov.

One detail is worth attention: according to Ukrainian officials, the corvette was escorting ships of the Russian „shadow fleet" - old tankers under flags of convenience, with which Moscow bypasses Western sanctions on oil exports. The war is long past being only at the front; it is on the seas, in the pipelines, in the accounts.

And as the drones reach ever farther, the question everyone in the Balkans asks themselves is quiet but real: if the deep rear of a superpower is no longer untouchable, what does that mean for the security of a small region dependent on others' guarantees?