The Economist: “…In practice, though, international law and the specific rules that govern warfare—the law of armed conflict (LOAC), also known as international humanitarian law (IHL)—give Israel considerable latitude to attack Hamas, according to legal experts. Article 51 of the United Nations charter gives states the right of self-defence against armed attack, provided that, according to customary international law, the force they use is necessary and proportionate. Proportionality does not mean symmetry in the type of weapons used or the number of casualties caused. It means that the defending state can use as much force as is needed to address the threat—and no more. Drawing that line is a subjective and contentious process. But Israel’s campaign so far would meet those criteria, argues Aurel Sari, a law professor at the University of Exeter who lectures to NATO armed forces. The scale of Hamas’s attack, its demonstrated intent and proven capability means that invading Gaza or even occupying it temporarily to destroy the group “will be relatively easy to justify” legally, he says…”