From a reader:

If we were only going to fight the wars that Rumsfeld envisioned, where we
blow up lots of enemy stuff and then leave in triumph, then robot soldiers
would be some kind of an improvement, metallic spiders with cameras and
weaponry scrambling through urban rubblescapes guided by remote pilots on
ships or airbases hundreds of miles away. But that kind of fight isn’t our
problem–adding capacity there doesn’t improve our already-incredible
performance that much.
The fights of the future look more like Iraq, where our real challenge is
how to provide security for the citizens, which requires telling the bad
guys from the good guys or the not-so-bad guys. That requires judgment, and
men, and casualties as soldiers risk their lives to bring peace to
civilians.
Bring on the robot soldiers when the robots are better than humans at
telling which local policeman by day is an insurgent by night.