Arbitration Commission of the Peace Conference on Yugoslavia
On 20 November 1991 Lord Carrington asked: "Can the internal boundaries between Croatia and Serbia and between Bosnia and Herzegovina and Serbia be regarded as frontiers in terms of public international law?" Applying the principle of "uti possidetis juris", the commission concluded on 11 January 1992, "The boundaries between Croatia and Serbia, between Bosnia and Herzegovina and Serbia, and possibly other adjacent independent states may not be altered except by agreement freely arrived at... Except where otherwise agreed, the former boundaries become frontiers protected by international law".
Battle of Kusonje
In 1990, ethnic tensions between Serbs and Croats worsened after the electoral defeat of the government of the Socialist Republic of Croatia by the Croatian Democratic Union ( – HDZ). The Yugoslav People's Army ( – JNA) confiscated Croatia's Territorial Defence ( – TO) weapons to minimize resistance. On 17 August, the tensions escalated into an open revolt of the Croatian Serbs, centred on the predominantly Serb-populated areas of the Dalmatian hinterland around Knin (approximately north-east of Split), parts of the Lika, Kordun, Banovina and eastern Croatia. In January 1991, Serbia, supported by Montenegro and Serbia's provinces of Vojvodina and Kosovo, unsuccessfully tried to obtain the Yugoslav Presidency's approval for a JNA operation to disarm Croatian security forces. The request was denied and a bloodless skirmish between Serb insurgents and Croatian special police in March prompted the JNA itself to ask the Federal Presidency to give it wartime authority and declare a state of emergency. Even though the request was backed by Serbia and its allies, the JNA request was refused on 15 March. Serbian President Slobodan Milošević, preferring a campaign to expand Serbia rather than to preserve Yugoslavia with Croatia as a federal unit, publicly threatened to replace the JNA with a Serbian army and declared that he no longer recognized the authority of the federal Presidency. The threat caused the JNA to abandon plans to preserve Yugoslavia in favour of expansion of Serbia as the JNA came under Milošević's control. By the end of March, the conflict had escalated with the first fatalities. In early April, leaders of the Serb revolt in Croatia declared their intention to amalgamate the areas under their control with Serbia. These were viewed by the Government of Croatia as breakaway regions.