A country loses its right to "re-establish deterrence" when the population it's "deterring" is born inside its own de-facto borders, and when the only reason it needs to deter so many of them is that they would (rightly) like one of a) sovereignty or b) voting rights inside the federal system that controls their borders and can kick down the doors of the houses they were born in.
If Israel would like to give Gaza full sovereignty, or Palestinians born inside the occupied territories the right to vote in the federal systems that determine their law enforcement environment, we can talk about deterrence and law enforcement respectively.
Israel has unilateral control of who it recognizes as its citizens, and what sovereign states it recognizes. No complaint about current or past bad behavior by the Palestinians excuses its failure to grant sovereignty or voting rights to people under its territorial control.
If Israel would like to give Gaza full sovereignty, or Palestinians born inside the occupied territories the right to vote in the federal systems that determine their law enforcement environment, we can talk about deterrence and law enforcement respectively.
Israel has unilateral control of who it recognizes as its citizens, and what sovereign states it recognizes. No complaint about current or past bad behavior by the Palestinians excuses its failure to grant sovereignty or voting rights to people under its territorial control.