In the classic Westerns, before the genre got all psychological and had people kissing everything except their horse and girl friend, there was a mandatory scene with a mandatory line. Early in the movie the bad guy would confront the good guy and say, “This town ain’t big enough for the two of us.” The rest of the movie consisted of everyone choosing sides, then the final, shoot-em-up, in which the good guy (against all odds) prevails. The classic version is Gary Cooper in High Noon. More complex is Clint Eastwood in The Unforgiven. The Byzantine version, in which a...