We should have just let Yugoslavia try the s.o.b. Then there probably wouldn't be this damn circus. This is fracking looney-tunes. It just shows that globalization sucks.
Then you'd need to have Yugoslavia under occupation first. It is not that easy to try virulent nationalists in virulently nationalistic places.
If he were tried in Serbia, he would have been dead, dead and more dead 3 years, 3 months and 30 days ago.
IMHO, leaders should be allowed to go into exile but denied any particular protection. From what I can tell, leaders generally become exponentially more cruel and despotic as their world collapses around them; rather than punishing them, it would seem better to encourage them to get out while they still have a few friends left.