Your plan has attractions, G23, to let them fight it out for themselves, with non-combatants out of the way, then return them when everyone was annihilated and the country was empty and ready to resettle.
I can't imagine there would be much left to return to though, and there could be an influx of outsiders to usurp the place of those temporarily absent. And those in the holiday camps would have no structure for keeping order, and a whole lot of time on their hands, which could lead to trouble between the camp dwellers and their neighbours. They would need screening anyway, for those (few but deadly) seeded amongst them who favoured terrorism and suicide bombing, and would recruit others from the dispossessed.
Would that we could wind the clock back! but we can oinly go forward from where we are, not back.