Ethnic Russians in Ukraine, take a note. Serbs and Croats in Bosnia, you too.
you can, but it's legitimacy is usually questionable

There are two major points contained within the Charter of the UN: territorial integrity of sovereign states, and people's self-determination. You can't have both, it's either former or the latter. Problem with the West's approach to Yugoslavian crisis was that it was dishonest and lacked basic consistency. West was constantly jumping from one point to another and back, twisting or overriding international laws and even their own previously established principles. You can't destroy one multinational country under the pretext that every constitutive nation has rights to choose its own path, and in the same time claim that Bosnia, another multinational regional country, must stay united at all costs and use sanctions and military power to keep Bosnian Serbs and Croats -also two constitutive nations- within its borders. Or to tell that all former Yugoslavian republics should keep their borders and to encourage some to crush secessionists (like Croatia was allowed to destroy Serbian rebels, or Macedonia Albanian rebels) and then, only several years later, to embrace rebellion of Albanian ethnic minority in Serbian province of Kosovo and support their secession.
This, my friend, is called politics of double standards - notorious Western specialty! It's not possible to achieve fair, long lasting peace like that, by giving everything to one side while taking everything away from another. Reality is black and white only in dumb Hollywood movies.
the Wests approach was to preserve Yugoslavia until Vukovar happened, after that the West leans on the other side, the West doesn't want a new aggresive country to prove everyone that they can go around invading countries and disobeying the rules of warfare

it is basically as simple as that, they did support Yugoslavia but when Serbs started the ethnic cleansing the rules changed so it's not actually double standards
also two constitutive nations
3 constitutive nations, 2 entities, 1 country
some to crush secessionists (like Croatia was allowed to destroy Serbian rebels, or Macedonia Albanian rebels) and then, only several years later, to embrace rebellion of Albanian ethnic minority in Serbian province of Kosovo
for starters, you can simply see war wouldn't stop if the Serbian rebellion wasn't stopped
Serb majority areas weren't connected and they were splitting Croatia in 2 parts, by simple means you can see it wouldn't stop there

Serbs would want to connect with their mother land trough lots of areas with Croat and Muslim majorities and along with Mihailovics plans leaving mayhem behind

while Kosovo is even connected to Albania
only other reason Serbs lost Kosovo was not double standards, it was aggresion on Croatia and Bosnia&Herzegovina
Americans saw Serbia as a new threat to international peace and as Serbs used force earlier they wanted to use it again
Westerners simply used them as an example that disobeying them won't be tolerated