Killer robots enable adventurism. Countries that have killbots will be tempted to use them. War will never be the same.
Assorted army robots.
All the technology shown in the movie is current. People simply haven't put it all together in one package yet, to our knowledge.
So in order to avoid this future, it's important to notify your politicians: It's immoral for machines to kill people. If someone is going to kill someone, it should be done by a person with a conscience-- someone who's going to weigh the pros and cons of pulling the trigger. Death by robot is obscene.
But America and some of the other armies of the world are working on serious robot killing machines with even more enormity than simple slaughterbots. Witness the following:
The U.S. Navy is now quietly building robot fighter jets that can take off, run missions, dogfight, and land by themselves.
The Navy is building boats with guns that can run in packs and drive themselves.
The Navy is building armed robot submarines that need no instructions.
Both the U.S. Air Force and Russia are building strategic bombers that can be flown without pilots.