I agree with both positive and negative reviews of the book, with the exception that I am ok with the quick conclusion. (It is the only thing that comes to a finale for Alan, anyway, if you know what I mean.)
I like the metaphor of impotence for the aging American salesman that goes hand in hand with the impotence of the American model for international commerce. Is the "promise" of more successful coitus for Alan a moral of the story, so that if America learns from its international competitors and shucks its special self-identity, it will be more complete, a western-Arab-Chinese hybrid? Does the near-assassination of the Saudi youth represent the current, poorly aimed, American self? But if so, why does Alan get off so easily? I mean, escape consequences, not "get off."