Perhaps we should go beyond paralleling the Russia-Ukraine situation to US-Cuba (the larger country previously held the smaller as a vassal, and though nominally independent it still enjoyed close ties, but a political upset in the small country left it aligned with the rivals of the large one, which at least manages to hold on to the territory it projects naval control over the regional sea from, and keeps trying for more)

And move on to Portugal-East Timor (the patron power left amidst imperial collapse, prompting neighboring forces to try and claim it for geopolitical purposes, but really more than that it had purpose in terms of the internal power structure of claimants, and might come loose again as that reshuffled and the issue lost relevance to regime structure)