The Communist regimes in Eastern Europe collapsed in the second half of the 1980s. The resultant processes of democratisation bypassed most of the republics of the former Yugoslavia, but not Croatia and Slovenia. The two republics proposed that Yugoslavia be reconstituted as a federation of sovereign states. Serbia, backed up by the jna (Yugoslav People's Army) refused the proposal. Croatia and Slovenia had no other option but to initiate the process of secession from the sfry. On 25 June the Croatian Parliament declared Croatia a sovereign and independent republic. Serbia and the leadership of the jna responded by launching armed aggression against Croatia. From the summer of 1991 to January 1992, when a cease-fire agreement was signed in Sarajevo, the jna and Serbian paramilitary units tried to inflict a decisive defeat on the nascent Croatian army in a bid to force Croatia to cede about a third of its territory to Serbia. The jna failed to achieve its two main geopolitical and strategic objectives : to decisively defeat the Croatian army and police force and carve up Croatian territory according to the plan to create a Greater Serbian state. In the first half of 1992 Croatia was internationally recognised and admitted to the un. However, a significant portion of Croatian territory was under Serbian occupation. Croatia had no choice but to use its armed forces to liberate the occupied areas of the country.
