I highly doubt American troops did not kill civilians. Wasnt there like over 100,000 civilians in Iraq that died like from somd kind of news i heard a year-ish ago? Forget, but i highly doubt American troops wont kill Iraq civilians (and may or may not give "oops" as an excuse ._.)
But yes if the definition has changed from a year ago then it is odd...i dont see why there should be a change.
