Of course, they should have realized a week ago that they were going to have to make this decision, because Qaddafi and his son are megalomaniacs. But they were probably hoping against hope that the army would flip like they did in Egypt. No such luck this time. Wishful thinking is not a foreign policy, as much as we would all like it to be.
Don't dick around with no-drive zones and military advisers. Either stay out of it entirely, or go get the bastard and put him in the Hague.