The "reason" was to encroach on Slavic space that we see as potentially being the "traditional Russian sphere of influence" and bait Russia by planting the second largest US military structure in the world Camp Bondsteel, on Serbian soil, without Serbia's permission.
The plans were on the table for building Camp Bondsteel in Kosovo, even prior to the 1999 NATO Bombing of Yugoslavia. And Bondsteel started going up right after the bombing. That's why, in retrospect, Bush HAD to grant Kosovo independence, after the fact. We weren't going to tear Bondsteel down and we couldn't have a military base on Serbia's soil without her permission -- so the solution was to steal the land from Serbia and give it to the Albanians who liked having us in the neighborhood to use against the Serbs.
Yes, it really was that cynical.
So you’re saying that Bush had no choice. Well Camp Bondsteel needs to come down just as the Ruskies need to leave Georgia. If Albania wants us in the area, we need to start negotiating a SOFA with them and build a base there. In fact, a base there would be better than in Kosovo because we have access to the Adriatic sea.
Earlier in the year when Bush’s state department recognized Kosovo I was flabbergasted and could not understand why. This may help explain things.