Operation Halyard: During the summer of 1944 approximately 1, 000 U.S. airmen bailed out over German-occupied Yugoslavia, a significant number of them landing in Serbia. In a series of daylight and night airlifts, a team made up of troops of General Mihailovic’s Royal Yugoslav Army in the Homeland and the Office of Strategic Services (O.S.S.) evacuated over 300 U.S. airmen from the village of Pranjani. The rescue of the U.S. airmen involved small unit actions against German troops and put at risk entire Serb villages that sheltered the U.S. personnel. U.S. airmen bear testimony to the significant sacrifices of local Serb villagers who fed, cared for and protected them, in some cases up to six months. The Halyard Mission is considered one of the greatest rescues of American airmen from behind enemy lines in the history of warfare.
Unfortunately, it didn't work out that way - because of the political ineptitude of Serbia. So it's better to have NATO effectively in control of Kosovo.
I do appreciate the friendship between the U.S. and Serbia in the past, and hope it will possible again in the future.