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".
Croat–Bosniak War
A Croat-Bosniak alliance was formed in the beginning of the war, but over time there were notable breakdowns of it due to rising tensions and the lack of mutual trust, with each of the two sides holding separate discussions with the Serbs, and soon there were complaints from both sides against the other. In February 1992, in the first of several meetings, Josip Manolić, Tuđman's aide and previously the Croatian Prime Minister, and Radovan Karadžić met in Graz, Austria. The Croatian position was not significantly different from that of the Serbs and held that Bosnia and Herzegovina should consist of sovereign constituent nations in a confederal relationship. In mid-April 1992, the HVO proposed a joint military headquarters for the HVO and the TO, but Izetbegović ignored the request. The HVO, on the other hand, refused to be integrated into the ARBiH. On 6 May, Boban and Karadžić met in Graz and formed an agreement for a ceasefire and on the territorial division of Bosnia and Herzegovina. However, the parties ultimately parted ways and on the following day the JNA and Bosnian Serb forces mounted an attack on Croat-held positions in Mostar. On 15 May, the United Nations issued resolution 752 which recognized the presence of JNA and HV soldiers in Bosnia and Herzegovina and demanded that they withdraw. In mid-June, the combined military efforts of the ARBiH and HVO managed to break the siege of Mostar and capture the east bank of the Neretva River, that was under control of the VRS for two months. The deployment of Croat forces to engage the VRS was one of the key obstacles for a total Serb victory in the early stage of the war.