If they find Gadhafi, what will they do with him?
A war crimes trial is real, yes. If in the Hague though it would be seen again as West imposing itself on the rest of World.
Killing Gaddafi would only make a martyr of him and inspire rebel forces to continue their resistance against Coalition Forces.So the diplomatic option would be to extradite him to The Hague in The Netherlands to face trial for international war crimes.
