Military robotics has reached an advanced state of development on land, in the air and at sea. The perceived military advantages has led to a proliferation of robotics programmes to more than 40 countires. Armed robots currently have a human in the loop to control the application of lethal force. But there is an inexorable drive to create autonomous robots that can choose their own targets and kill them. There have been no international discussions about how such systems could impact on how wars are fought or what the likely effect will be on civilian populations.