There is no gap in the law. As I said in the article, the law prohibits the _disproportionate_ destruction of civilian life and infrastructure relative to the military objectives achieved.

Perhaps I will write another article looking at some legal precedents that have established the meaning of “disproportionate” but my point here is that killing 100 civilians for every legitimate military target is likely disproportionate.

You ask what Israel is supposed to do. As another commenter pointed out, when the US sent its special forces into Pakistan to take out Osama bin Laden, they succeeded without loss of innocent life, even though some inhabitants of the compound tried to use children as human shields.

What Israel needs to do is assume the risk of its legitimate desire for justice and use boots on the ground to clear tunnels and occupy buildings. Yes, many more Israeli soldiers would die, but that’s what happens when you invade a country.

I didn’t talk much about this issue, though I discussed it at length in a previous piece (see Israel’s Forever War), but if you can’t drop a bomb in Gaza without killing ten civilians, that is largely Israel’s fault. They have pursued a strategy of “ghettoizing” as many Palestinians in Gaza as possible, routinely granting relocation requests from West Bankers who want to live with relatives in Gaza, but denying the same requests when made my Gazans who want to live with relatives in the West Bank.

The idea is the drain the West Bank of Palestinians so that Jewish settlers can take their places, and this has been achieved by cramming as many people into Gaza as possible.

Having crammed them all in there, Israel cannot now complain that they can’t bomb Gaza without killing children. Rather, Israel’s army is obliged to shoulder the risk of invasion themselves, even if it means more Israeli soldiers will die. At least the soldiers signed up for that. You can’t say the same for Palestinian children.