I found this clip by Boston Dynamics both impressive and scary.
https://www.youtube.com/watch?v=tF4DML7FIWk
It seems the world is heading rapidly towards highly impersonal wars (at least for the US, China and Russia). The obvious problem being that impersonal killing is dispassionate and much easier than the face to face stuff. Humanity and empathy fly out of the window.
If you want more in the same vein the History Channel has a recent documentary.
https://www.youtube.com/watch?v=-y-5fqIjdRQ
Time for us to join Sweden in the ranks of the non-aligned methinks.