as i said earlier, Mohammadan law is easier to cover for people to cover with no background in law. If you are fascinated by International Law, go all for it. Read everything you have on the subject, from the view points of grotius, to latest interpretation put on it by the neo liberals. But for those who would want a paper to look for to save time, i would always recommend Mohammadan law.
just take time to go through the jurisprudence parts. they can take most of the time but are the most interesting as well.