Death of a Nation

In August 1990, an unrecognised referendum was held in the Krajina region (bordering western Bosnia and Hercegovina, with a large Serb population at the time) on the question of Serb "sovereignty and autonomy" in Croatia. This was to counter the changes of constitution. The Croatian government tried to block the referendum by sending police forces to rebeling police stations in Serb populated areas to seize their weapons. Among other incidents, local Serbs blocked the roads to the tourist destinations in Dalmatia. This incident is known as the "Log revolution". The government responded by sending special police helicopters, but they were intercepted by Yugoslav Army fighter jets and forced to turn back to Zagreb.

On December 22nd, 1990, the Parliament of Croatia ratified the new constitution, changing the status of Serbs in Croatia to a 'national minority' from a 'constituent nation'. The percentage of those declaring themselves as Serbs, according to the 1991 census, was 12% (78% of the population declared themselves as Croat). This can be read as taking away some of the rights from the Serbs granted by the previous Socialist constitution, thereby fuelling nationalism among the indigenous Serbs of Croatia. Or the new constitution can be read as granting Serbs in Croatia the same status as other minorities.

Consequently, many Serbs began to lose their government jobs in Croatia, particularly after the ratification of the new constitution. This thereby further escalated tensions.

Furthermore, Slovenia was also well into its own process towards independence. On 23 December 1990 - one day after the new Croat Constitution was passed - Slovenia held a referendum on independence. This passed with 88% of the vote.

Immediately after the Slovenian referendum and the new Croat constitution, the Yugoslav People's Army (JNA) announced that a new defence doctrine would apply across the country. The Tito-era doctrine of "General People's Defence", in which each republic maintained a territorial defence force (Teritorijalna Obrana or TO), would henceforth be replaced by a centrally-directed system of defence. The republics would lose their role in defence matters and their TOs would be disarmed and subordinated to JNA headquarters in Belgrade.

-http://en.wikipedia.org/wiki/Croatian_War_of_Independence