South Sudan was a Sudanese territory and Kosovo was a Serbian territory.
i won`t go into Sudan but, as for comparison of Kosovo to Crimea, just few words.
First of all, both- Kosovo and Crimea are autohtonous Slavic (Proto Slavic/Sarmatian/ie Sythian) regions.
Russian state was born from within Kievan Rus. In the meanwhile Russian ethos consolidated. With time, Ukrainians followed. Also, Ruthenians followed. Not to say that Poles also have historical connection to the territory of what is today`s Ukraine. So, Slavs there needs to talk. They all have same rights, considering that, as Slavs- they are all autohtonous population. They all have their specific characteristics and interests. All that have to be respected. They needs to learn to share their history. So far, what i heard, new Ukrainian authorities (BDW, same as old ones), speaks only of Ukrainian and Russian rights. Nobody asks Ruthenians. Nobody asks Poles. Not to say that you have region in the Ukraine populated with Serbs from Balkan in the middle age. Region was given to them legally by back then official Russian state institutions. Nobody ask them of anything now (ever). Not that i complaint. i don`t complaint. Nobody asks Serbs even in Serbia for Serbia, so why ask them in Ukraine.
Let all sides in Ukraine talk and negotiate as long as possible. They all have their rights. Let us Slavs prove to be competent in Slavic world, if we don`t wish that hostile non-Slavs arrange how we should live.
Now, as for Crimea specifically. Russian state, statehood, ethos and culture invested a lot of in the region. Nobody asked ethnic Russians when Soviet communists simple drown borders of the Soviet Republic of Ukraine. Actually, nobody asked even Ukrainians. So, in case with Crimea, we have false dilemma. If we were to follow logic that all negative things done by communists needs to be corrected, if possible, then- its alright that ethnic Russians vote and decide for Crimea to join with Russia.
On the other side, Kosovo and Metohija (two regions in short called just Kosovo) has nothing to do with deeper Albanian history, while has all with Serbian history in any sense (culture, statehood, religion, archeological sites). Even North of today`s Albania (Malesia region) was Slaveno-Serbian in the middle age and just with arrival of Ottoman Turkish invaders things changed. Due to Turkish intervention ethnic structure of Malesia/Kosovo changed on the behalf of Albanians. Then, Italians continued where Turks were stooped, during WWII. Not to mention Albanian pogroms over Serbian during WWI when Serbian army temporarily needed to retreat out of Serbia pressured by Austro-Hungarian and Bulgarian attacks. Finally, NATO/EU/Islamic league leading powers intervention in 1999, ultimately changed ethnic balance on Kosovo on the behalf of Albanians. Under their supervision, Albanians- ethnic minority in Serbia, separated Kosovo from Serbia.
Do you people know that USA congress voted to support thesis of Albanian nationalists who state that are Slavs newcomers to the region and so, that Albanians have all rights to prevail on Kosovo? Yes, USA congress support this kind of thinking.
It is especially interesting that from about century in the past Italians, then Austrians too, now already followed by entire EU, normally using designation Albanians, while Albanians, STILL, call themselves Squitary (in Serbian- Shiftari). Just go google or Wiki about it and see it for yourself. So, non-European population that was fist of Turkish invasion on Slaveno-Serbs is declared to be native on Kosovo. In that spirit, west of Europe changing ethnic name of that people from Squitary to Albanians (BDW, Albanians- is from Slavic Alba and means `belo`- `white` in English), while is native Slaveno-Serbian population forced on assimilation and to abandon region.