...the international community did not accept Kosovo's claim to independence. The late Bush administration started on December 25, 1992, with President Bush's famous Christmas warning, telling Milosevic that he should not abuse the human rights of the Albanians of Kosovo, but that Kosovo was part of Serbia. This was a very complicated equation. But it was the position of the Clinton administration, and the Europeans inherited and held to it.
Holbrook is obviously mistaken on that count, as anyone can see by reading the actual warning themselves. Given that he discussed the matter with Milosevic at Dayton and later, there's a possibility he's confused his discussions with the content of the original warning - the Christmas warning says exactly what is says, and nothing about Kosovo being a part of Serbia.