While I think Michael Moore’s misguided “coward” remark about military snipers was a disservice to our military people, the movie itself is fair game for thoughtful criticism. This is what Chris Hedges, a prominent journalist and author, said about it:
“’American Sniper’ lionizes the most despicable aspects of U.S. society—the gun culture, the blind adoration of the military, the belief that we have an innate right as a ‘Christian’ nation to exterminate the ‘lesser breeds’ of the earth, a grotesque hypermasculinity that banishes compassion and pity, a denial of inconvenient facts and historical truth, and a belittling of critical thinking and artistic expression.”
http://www.commondreams.org/views/2015/01/26/killing-ragheads-jesus-watching-american-sniper
That’s strong language, and maybe it’s justified, maybe not. I haven’t seen the movie, so I can’t judge. Clint Eastwood, in the twilight of his Hollywood career, has morphed from an actor in Western and cop action flicks to a director of noir films telling morally ambiguous stories. Hedges’ critique of Eastwood’s latest cinematic artwork may be unfair or at least overstated. Making a movie about sniper combat doesn’t ipso facto endorse the violence and immorality of war.
I came away from watching Eastwood’s previous effort in “The Unforgiven” with a sense that he imagined a pitiless world and then searched for grains of compassion in it. After that movie, I can’t visualize Eastwood “lionizing” guns or violence or the oppression of people, and my gut reaction is that it’s unfair to label or stereotype his work in this manner. He impresses me as a man who is genuinely distressed by the human condition and its moral shortfalls, and his recent films exude a sort of anguish. That is dead opposite to Hedges’ characterization of his new film. 
Photo credit: Common Dreams. “Actor Bradley Cooper (r) playing U.S. Navy Seal sniper Chris Kyle in the film ‘American Sniper.’ (Photo: Public domain)”