Mulisch visited Cuba twice. Once by order of the monthly magazine Avenue but in January 1968 he was invited by the revolutionary government.
In the preface of het woord bij de daad Mulisch writes: 'Cuba changed my life for the better, which had deteriorated seven years ago in Jerusalem. Eichman taught me about right-hand ideologies; Fidel Castro what actually can be done. However, this doesn't make him a God because Eichman wasn't a devil either. Castro is a good man in contrast to a bad man: a man against a machine. It's the same struggle that is currently fought in Vietnam'.