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".
Croatian War of Independence
The JNA initially tried to keep Croatia within Yugoslavia by occupying all of Croatia. After this failed, Serb forces established the self-proclaimed Republic of Serbian Krajina (RSK) within Croatia. After the ceasefire of January 1992 and international recognition of the Republic of Croatia as a sovereign state, the front lines were entrenched, the United Nations Protection Force (UNPROFOR) was deployed, and combat became largely intermittent in the following three years. During that time, the RSK encompassed , more than a quarter of Croatia. In 1995, Croatia launched two major offensives known as Operation Flash and Operation Storm, which would effectively end the war in its favor. The remaining United Nations Transitional Authority for Eastern Slavonia, Baranja and Western Sirmium (UNTAES) zone was peacefully reintegrated into Croatia by 1998.