That just isn't true at all[1]. Since the end of the Second Congo War[3] (in 2003) there hasn't been a conflict that's come close to 1MM causalities.
While the Iraq, Afghan and Syrian wars have been brutal and very well publicised they haven't been anywhere near as severe in terms of causalities.
(Don't take this as a comment either way on US policies though)
[1] https://en.wikipedia.org/wiki/File:List_of_wars_by_death_tol...
[2] http://www.smithsonianmag.com/smart-news/globally-deaths-war...
[3] https://en.wikipedia.org/wiki/Second_Congo_War
