Nationalism is a poison. It attacks the mind, short-circuits thinking, and makes self-destruction look appealing. Nationalism sows the seeds of hate and war. It makes the title warrior an honorific instead of the pejorative it ought to be. And it's the reason for the venom directed at those of us who question American sniper Chris Kyle's status as a hero, writes Sheldon Richman. We see naked ugly nationalism in many defenses of Kyle. Defenders appear to have but one operating principle: If Kyle was an American military man and the people he killed were not, then he was a hero. Full stop.