And whose troops will make up that deployment?
I'm sure your belief in UN deployments is heartfelt but it's naive. The UN has no troops of it's own. That being the case, it has to get member nations to send troops under the UN banner (complete with pretty blue berets and helments that make dandy sniper targets). What nations do you think will send their troops into that mess? Hammas has absolutely no desire in peace, so they'd have no hesitation with killing UN troops any more than they'd hesitate to kill Israeli troops.