Unconditional surrender, round them up, execute them but let their families live.
Follow the General Pershing plan.
Execute all but one.
Let him escape and tell about how the executions were carried out with bullets dipped in lard and mass graves littered with pig carcasses.
No "72 Virgins" for you, infidel!
That’s just delaying terrorism until the male children grow up and the widows have time to make more terrorists.