Israeli war crimes?

Eric Posner, at the Volokh Conspiracy, has a post on The Gaza Conflict and the Limits of International Law.

Here are the high points:

1. Jus ad bellum. Gaza is not a state. It’s not clear what it is—occupied territory? Mandate? If it’s not a state, the UN charter does not forbid an attack. Even if it were, the UN charter would not forbid an attack as long as Israel’s attack is in self-defense—which it appears to be, so far.

2. Jus in bello. Can there be a war between a state and a non-state entity? Yes! And most people think the regular laws of war apply. The laws of war forbid the deliberate killing of civilians, but so far no one has proved that Israel has deliberately killed civilians. That leaves the proportionality rule, which bars an attack that causes civilian casualties (or property damage) that are “disproportionate” to the attack. Unfortunately, no one knows what proportionality means. Can you drop a bomb on a Hamas leader that might or will kill a nearby civilian? Two civilians? Ten? A thousand? Does it matter how important the leader is? Whether he has taken refuge in a densely packed area? There are no settled answers to these questions.

3. Human rights. Ideally, the Israelis enter Gaza and arrest the rocket shooters and their leaders, try them, and convict them if they are guilty. In practice, this is impossible. Human rights law does not prohibit the use of violence when ordinary law enforcement practices are inadequate.