Hamas has announced it will not "protect Israel from attacks by other factions". There is nothing new about this idiotic line of reasoning, of course, and it has been one of the standard canards ever since Israel began disbanding its occupation and transferring power to the Palestinians in 1993.
The question is not if the PLO, or PA, or Hamas, or anyone else, will protect Israel from the more extreme Palestinian forces that will always continue with their anti-Israeli violence no matter what agreements are reached. The question is if whatever Palestinian government it may be will take upon itself one of the most basic of all tasks of government, the monopoly of waging violence. As long as they don't understand that this is a fundamental need of their own, irrespective of Israel, no peace agreement with them will ever hold. On the contrary, the longer they insist on behaving like little children, the more obvious and irrevocable it will be not to allow them a government. Governing is a matter for adults.
[Which doesn't mean Israel should continue to control them. More and more I am beginning to think there will ultimately be not choice but to hand over some sort of control of the Palestinians to the Jordanians and the Egyptians.]