If Israel did so, Hamas would rampage and slaughter the people of Israel just as they did Oct. 7.
If Hamas did so, on Oct. 6 they would have lived in peace. If they did so now, the civilians of Gaza would live in peace, and Israel probably would downgrade its activities even against the Hamas organization specifically.
This indeed is the key issue in every war, which by its very nature is a failure of both politics and of "justice" of the bewigged variety. There is no "justice" in war, only the right to self defense which Israel alone reasonably claims here. I tend to be sympathetic to international institutions like the ICC, but this demonstrates it's either corrupt or impractical or both.