Would using robots as weapons be ethical?

Ok this might sound like something from The MAtrix or Terminator but seriously, we are moving towards a complete machine controlled society and that leads to obvious problems. I am personally hoping that we decide against the use of auto soldiers that could fight wars for humans, through a Geneva Convention like approach and ban the use of them. (believe me, if not I will take on the responsibility and lead a movement against it) I mean seriously would you go to sacrifice your life for your country if you knew you were up against something that you couldn't kill under any cirstances, a machine that completes its task under any cirstance. Would you think that it would be fair?