We are the most effective killers in the history of mankind.
And while not keen to do so, we can pull out that bag of tricks again.
From another FR thread: Why They Behead Us: — “Instilling fear is one. But War Trophies is the other. Displaying body parts of the enemy publicly is a very old practice. Visually & symbollically, the head of a dead enemy sends a particularly powerful message. War trophies are actually banned by (western) military law.” — http://www.freerepublic.com/focus/news/3204175/posts?page=50#50