You raise exactly the right question. Here is where I think we are right now. There are two possible military missions that would require the use of ground troops. The first would begin with a rapid deployment of those NATO (which is to say chiefly U.S.) forces that can get into Kosovo within the next few days to halt the Serb offensive and create an enclave for the Kosovar Albanians. This would be a holding action while a larger force was assembled that could then come in and push the Serb forces back across the provincial border into Serbia. The political goals of the mission would be, first, to halt the slaughter in those parts of Kosovo where we could, and second, to expel Serb forces from the province.
I fear, however, that Clinton's reluctance to use ground forces in the near term is likely to make the first phase--the rescue operation--impossible. It seems to me the United States would have to move immediately to have any meaningful impact inside Kosovo. Within a few days or at most a couple of weeks, Milosevic is likely to have drained Kosovo of almost the entire Albanian population. (By the way, I am not at all convinced that he is merely playing for a partition, bad as that would be. Given NATO's ineffective response so far, why should he give up any part of Kosovo?) That will leave us facing the kind of fait accompli that Saddam Hussein presented the world in 1990. He took Kuwait without opposition and then dared the U.S. to drive him out.
The second scenario involving ground forces that I would envision, therefore, is an operation not unlike the liberation of Kuwait. (I leave it to you to explain the differences between the two situations--terrain, troop concentration, etc.) The United States would, in essence, accept that Milosevic had won the first phase of the battle for Kosovo, just as Saddam won the first phase of the battle for Kuwait. Our goal, like Bush's in Desert Storm, would be to reverse that victory. The political goal of the military operation would be the reconquest of Kosovo. If it took several weeks to deploy the necessary forces to maximize the chances of success and minimize casualties, so be it. It was five months between Saddam's conquest of Kuwait and the initiation of Desert Storm.
In this second scenario, I would also consider taking the war to Milosevic on two other fronts: in Montenegro and in Bosnia. I don't see why we should necessarily limit ourselves to undoing his latest outrage. Why not deal him significant defeats elsewhere, by liberating Montenegro and destroying the power of Karadzic and Mladic in Bosnia?
I have not addressed the question of going into Belgrade to take Milosevic out once and for all. Maybe we can discuss that in the next round. But I'd like your reaction to these other scenarios. Are the political goals straightforward enough? Do the political objectives match up with military reality? What are the downside risks that I'm not adequately considering? I look forward to your thoughts.