The thought, which presumably is not original, occurred to me upon seeing Increasingly, Robots of All Sizes Are Human Workmates (a step toward the integration of human & machine?).
A possible itinerary: from human-operated drones to human-operated robot warriors to autonomous robot warriors with a human overseer. Whereupon some genius will claim it's perfectly safe and more cost-effective to give the things full autonomy...
Added 20140426: The Russians are going directly to Terminator mode (HT: Instapundit):
Armed Russian robocops to defend missile bases
THE West has always been a little squeamish about the idea of arming robots. Despite decades of development, no systems have ever been deployed and a vocal human rights campaign means it's unlikely to happen in the near future. The Russians, on the other hand, appear to be rather less concerned.
Last month, Dmitry Andreyev of the Russian Strategic Missile Forces announced that mobile robots would be standing guard over five ballistic missile installations. These robots can detect and destroy targets, without human involvement. Russia, it seems, is taking the lead in a new robotic arms race.