The main themes in the novel concern the nature of love; whether or not to become involved in love or in politics; and, finally, the nature of illusion and the difficulty of distinguishing, as the motto of the book puts it, "the good side from the bad, the Captain from the enemy." These are essentially the same themes Greene raises in The Quiet American, but here the emphasis is much more on the personal than the political. By the end of the novel, Jim appears to be a lost soul, not so much because he chooses the CIA instead of the Sandinistas (which, in Greene's mind would be an unwise political choice), but because he chooses to trust Quigly, the enemy, rather than the Captain. His journal has not helped him to understand love — which, for Greene, seems to be a simple, basic response between people who need each other — or how to see behind the illusions. In that sense, the book also suggests that writing itself may be suspect, because it brings Jim no closer to love or to reality.
(The entire section is 181 words.)