In 1927 Chiang Kai Shek boiled hundreds of Communists alive, and yet within ten years he had become one of the heroes of the Left. The re-alignment of world politics had brought him into the anti-Fascist camp, and so it was felt that the boiling of the Communists ‘didn't count’, or perhaps had not happened. The primary aim of propaganda is, of course, to influence contemporary opinion, but those who rewrite history do probably believe with part of their minds that they are actually thrusting facts into the past.