The Kosovo precedent is baleful enough without deciding on the basis of it that sustained banditry and military responses to put it down form a sound basis for partitioning countries. By that reasoning the Russophile Eastern Ukrainians just need to sustain guerrilla action against Kiev for a few years have Kiev try to restore order militarily and hey-presto there's an argument FOR their secession. (Repeat in Catalonia, Scotland, the Veneto, Sardinia . . .)
Well, sustained violence is indeed one factor, but balancing it should be another: the party with a grievance must have also leadership that restrains violence rather than seeks to profit from it. And there are others: a referendum conducted without haste, with impartial international observers, and an agreement from all the parties concerned to respect its outcome. In Kosovo, — I am not defending Kosovo independence by the way, — we have at least an effort to adhere to the above principles; in Crimea all we have is farce and intimidation.