So what could Israel have reasonably done? Bombing the tunnels through which Gazans smuggle weapons would have been a proportionate response, if Israel had stopped there, and the same is true of airstrikes on certain Hamas targets. An even better approach would have been to ease the siege in Gaza, perhaps creating an environment in which Hamas would have extended the cease-fire. It was certainly worth trying — and almost anything would be better than lashing out in a way that would create more boomerangs.