I disagree with you third opinion. You said using robot could be a tool to slaughter the enemy more cruelly. But it couldn't slaughter the people. According to Three Laws of Robotics, robot must not harm to human. In other words, robot like jet or tank of America is made to threaten other countries to protect their country. In addition, utilizing robot in military tools is human. If we prevent human from using robots, there are still many other choices like nuclear bomb. So, I think it is a mistaken notion to attribute the danger of slaughting to robots. People should change first.