Europe, inc the UK buying Russian energy isn't why we are here, some might not know but even during the height of the Cold War, the 'West carried on buying raw materials from the USSR... if you don't want 3rd world starvation, where do you get grain from? EV's? Where will the nickel come from for their batteries etc?
Russia felt enabled to invade because we did nothing over Georgia, Crimea, Salisbury poisonings, allowed Putin to buy the Tory party, buy Brexit, most of London and we told the Russians we wouldn't intervene if they did invade... stupid, even my cousin who was a lowly NCO choked on his coffee when he heard that one.
But its what we do next that matters, opening up the Black Sea is probably the most risk free thing we can do, whether the USA has the political will to do so is another matter, Europe hasn't the means to do it, esp the UK after years of naval cuts, leaving us with around 19 frigates, with only 7 that can be deployed.
If the US wont do it, then Europe needs to get off its arse and send anti ship missiles, even if that means using "contractors" to operate them, plenty of ex services are in ukraine already.
Apparently the UK has among the best ones, so over to BJ to do the walk.....