Retief, a junior diplomat in the Corps Diplomatique Terrestrienne, is competent, intelligent, and very effective. (Also, he's always willing to ignore procedure in favor of common sense.) This means that he doesn't rise above junior diplomat, in an interstellar diplomatic organization that is made out to be managed and populated by the corrupt and the moronic. On the other hand, he always manages to save the day, so his credit-stealing superiors continue to allow him to remain a diplomat.