Good. We gave piece a chance. They rejected it. Now kill them.
It goes without saying that Hamas will have to be destroyed.
Israel has a chance here to deal. Demand that the UN withdraws and dismantles UNRWA and that Hamas return the hostages (or their bodies, which is likely) in 24 hours, or Rafah gets leveled and all UNRWA personnel will be rounded up and expelled after they've been processed for a while.
The UN will reject this. The League of Nations failed collapsed because it wouldn't and couldn't do anything about the very problems it was set up to avoid. It's the UN's turn.