Here’s a warning: Don't see this movie if you can’t stand violence or want clarity about who the good and bad guys would be in a potential civil war. Do see the movie if you can stand the disturbing violence and if you care not to let our country descend into civil war. In an appropriately disturbing way, the new movie is a wonderful warning - for two reasons. First, it is masterfully constructed and shot.  All the actors are effective.  The soundtrack is clear…