Posted on SSRN is an exchange on the legality of Israel's Operation Cast Lead between Prof. David Luban (Georgetown) and Prof. Amos N. Guiora (Utah). Luban argues that the operation violated both jus ad bellum and jus in bellum requirements, Guiora argues that it did not. It constitutes a stellar example of a fair-minded, scholarly inquiry on a subject of passionate concern.
I highly encourage you to download and read the whole thing (it's not unreasonably long). Perhaps the most interesting point was the agreement between Luban and Guiora that Gaza should not be considered "occupied" under international law. Luban came to this conclusion for two reasons: First, labeling Gaza as occupied would impose obligations on Israel to interfere more heavily in the Gaza strip (specifically, it'd have to actively govern it), which is the opposite of what everyone wants. Second, and more pragmatically, Luban observes that "genuine occupying forces -- which, in the words of the International Court of Justice, have 'substituted their own authority' for that of the government (Uganda v. Congo, decision of Dec.19, 2005, para. 173) -- do not have to fight their way in."
But the discussion encompasses a far broader range of topics: proportionality, the way the law of war interacts with asymmetric warfare, whether or not Hamas infrastructure writ large is a legitimate military target, and many others. I again give it my full recommendation.
Via Paul Cassell