What metaphors are used in A Fire upon the Deep by Vernor Vinge?

Much of the narrative can be seen as a metaphor for Genocide. While the Milky Way Galaxy generally enjoys peaceful coexistence of thousands of sophonts (intelligent beings), it is stirred up by the outbreak of the Straumli Perversion (or Blight) to extreme prejudice against homo sapiens and eventually genocide. Many voices call for calm reasoning: a few greedy individuals accidentally release the Blight, whose first victims are humans, simply because they are the chief inhabitants of the Straumli Realm. These voices decry the idea of collective responsibility requiring collective reprisal.