What is the main theme in the novel, The Captain and the Enemy?

The Captain and the Enemy is basically a story about love, where politics is a last option, to be pursued only when love can no longer be. Although it is about love, it is not a conventional "love story." Most of the novel is presented as a journal written by Jim as he attempts to understand the unusual but loving relationship between his foster parents. He must also come to terms with his own realization that love is an emotion he cannot feel.