Or maybe it was the Croats, Bosnian Muslims, and Albanians who saw Serbs as threats to their territories' independence.
Croats, Muslims, and Albanians were killing Serbs from the very beginning - even before the beginnings of these wars. Serbs were being discriminated against and kicked out of their jobs in Croatia, for instance.
That is why the first refugees in these wars were Serbs from Croatia. I believe the grand total number of Serbs who left Croatia during the '90's is over 600,000.
It is Croatia's demographic picture which seems to have been most permanently changed in the recent Balkan wars - its population was 12% Serb in 1991, but now is supposedly only 2-3%.
(Given 12% of the population of Croatia, 600,000 is more Serbs than were living there to start with, methinks).
Croatia has census information on the web, but it doesn't have an ethnic breakdown. I'll wait for that to come out, rather than relying on 'supposedly', no offense.