The Iraqi army has collapsed again in the face of a few hundred ISIS insurgents: what you get when you seek to impose a western-style military model on a faction-riven clan/tribal society. Understandably, the Americans don't want to put their own troops in harm's way.
I wonder what the Pentagon would say if you offered them land drones? I have in mind a small tank, about the size of a Toyota saloon. It would come with Google car autonomous navigation, with strategic direction from some guy in a carrier a few hundred kilometres offshore.
With high quality video fed into the operator's VR headset and a rich weapon set this must be virtually isomorphic to Quake or any number of FPS games. I would add a big, built-in explosive device: if captured or immobilised we'd get a drone suicide bomber.
Why don't we see land drones in action already? Well, it shouldn't be long, but I would bet the big problem is logistics. Keeping the devices fuelled, weaponed-up and maintained in hostile terrain seems to be the hard problem here.
A further thought. With a network of drones (reconnaissance, assassin, applied lethality) it becomes possible to develop a detailed realtime model of the battle space. The controlling tactical AI then becomes a critical systems element - the chess grandmaster of force deployment.
On our side, at least, war is just another game.