Throughout history wars have frequently resulted in changes of borders. NATO's military intervention of 1999, however, ended without a clear outcome regarding the future of Kosovo. After three months of bombing targets in Kosovo and Serbia proper, NATO finally managed to obtain the withdrawal of the Serb security forces from Kosovo and the establishment of an interim administration by the United Nations. UN Security Council Resolution 1244(99) confirmed in its preamble the territorial integrity of the Federal Republic of Yugoslavia. At the same time, however,it left the future status of Kosovo open, as it empowered the civilian presence to 'facilitate a political process designed to determine Kosovo's future status, taking account the Rambouillet accords.'