Absolutely Hamas violates that principal IMHO, but since I don't work as a UN prosecutor that opinion and a dollar two ninety-eight will get you a cup of house drip coffee.

Also, IMHO, I don't feel dropping leaflets exonerates Israel from a response excessive in relation to the concrete and direct military advantage anticipated. They're still blowing up houses and infrastructure unnecessarily, which is excessive and appears as collective punishment.

Funny thing about those leaflets, although I do believe Israel's intentions are good, where exactly do they expect the Palistenians to go considering Gaza is one of the most densely populated areas in the world. Is the message something like, "Hey, we're getting ready to bomb the schyt out of grid square A, so you need to move your collective asses to grid square B. Tomorrow you can move back to A 'cause then we're gonna bomb B."