Sun Tzu made an observation, some 2,500 years ago, that modern coalition politics seems to have taken to heart, though no one credits him for it. Paraphrased loosely: an army does not need every soldier to want the same outcome. It needs them moving in the same direction until the battle is won. The Red and the Green appear to have absorbed the lesson without ever reading the book. Almost nobody asks what happens once the battle ends and there's no shared enemy left to hold the army together. The Red is the socialist left. The Green is political Islam....