It get messy trying to define combatants, terrorists, legitimate targets, etc when you can't identify your enemy (the guys trying to kill you). We're fighting ideology and not a country. In this case, kind of like the crazy kamikaze pilots of WWII, the concept of killing oneself to take out a target, is foreign to us (even after 100s of years of Islamic knuckleheads doing stunts like this). Most of us, in war, would rather kill the enemy and live so that we can come back another day and kill more enemy.