They get young children who have been brainwashed in madrassa schools for years to strap on explosives and blow themselvs up.
Now what is rational about that--it's total brainwashing from cradle to grave in many cases.
The news footage of uniformed Hamas or Hezbollah storm troopers goose stepping on parade or giving the "seig heil" stiff arm salute are truly frightening, particularly the ones of preteens. You cannot reason with people in that condition. You can only kill them. Preferably with as little other damage as possible, but that has to be a secondary consideration.
Once again I reiterate just how key it is for locals in these areas to stop all this madness before it ever gets started. IT only exists with the acceptance tacit or not of the local populations.