They need to trade with people for money and food. If their closest neighbor let them trade, I guarantee Cuba would be saying the opposite to stay on the good side of them. But since they can’t, and Russia was iced out of the world economy pretty much, of course they’d extend a hand to Cuba, which is similarly iced out. And of course they’d accept for the good of their people. Who knows if they actually care how that war goes, they’re just a tiny island nation that wants to be able to eat and survive. We can’t blame them for making decisions under this kind of duress.