"Did Tito keep them all together through fear?"
Yes, and with backing of the US. It was in US interest to keep the country together, but no one ethnic group was singled out more than another for this treatment. It was just that some had more of a seperatist movements than others and wound up in jail more often.
The Croat seperatist movement had been going on a long time by 1991. Back in 1976, a plane from NY to Chicago was hijacked by Croat seperatists.
"September 10, 1976 Terrorist Zvonko Busic, his wife and three other Croatian terrorists, as a result of concerns about the plight of Croatia within then communist Yugoslavia, hijack a TWA jetliner from LaGuardia Airport, bound for Chicago and re-routed to Paris, seizing 86 passengers. There were no weapons aboard the plane, but genuine explosives were left behind in a Grand Central Station baggage locker in order to create the impression that there were weapons on the plane. Bomb Squad Officer Brian Murray tragically lost his life attempting to deactivate the bomb."
Three moderate Croat businessmen in the US were also murdered by this same group of hijackers. Today, Julienne Busic, one of the hijackers is part of the Croatian government. She is an American who justifies so conveniently what she did that killed a man, that it is scary to me. http://www.asi-mag.com/editorials/busic.htm Do I believe her shoot out in the streets of Paris story? No. Yugoslav agents tracking her all over the world to kill her? Give me a break! Yugoslavia wasn't rich enough or stupid enough to send out that kind of dragnet for her and her husband.
But the point is that it took a while, but the Croat separatists finally found a backer in Germany.