When you replace army troops with mercenaries, you're giving up the battle. I wonder if we'd have as much trouble in Iraq if during the invastion, instead of using precision munitions to take out military targets, we'd simply firebombed the major cities and killed civilians to the extent we did in Germany and Japan. Instead of an Iraqi combatant simply melting into the general population, by eliminating the general population the Iraqi combatant would have no place to hide.