In a situation where one of the belligerents has offered to negotiate a cease-fire, the choice is clear. It is legal to negotiate a cease-fire, but it is a war crime to use collective punishment as a way to avoid having to negotiate.

Hamas has offered to negotiate a cease-fire. Israel has refused and is instead using collective punishment for the purpose of trying to avoid negotiations. Israel is using collective punishment of a civilian population as a kind of defacto negotiation. This is a war crime.

Even when Hamas was unilaterally engaging in a year long cease-fire, Israel did not stop its bombing of Gaza. Hamas has every reason, based on past experience, to expect that if it stopped firing rockets into Israel right now, Israel would not stop bombing Gaza.