Rereading what I wrote, I suppose I subscribe to the UN model
  more than any other. American Imperialism is a growing problem
  worldwide, except in the USA where we just think we're normal. I
  remind myself of that sometimes but not always easy to remember.
    That's a very good question. I'll have to think about that
  one. We have had periods of Imperialism and isolationism in our
  250 year history and we seem to be in an Imperialist phase.

  Why that is, I'm not really sure. It's a very good question.
  There's a documentary made by the BBC a couple of years ago
  about American Imperialism that's on my "going to watch this
  sometime" list, as I'm trying to broaden my perspective about
  the impression of my own culture in other parts of the world,
  but i haven't gotten to it yet.   I'd also like to find
  documentaries made in other countries as well, for while the
  "BBC Perspective" is common (and forms the basis for a lot of
  our own understandings of history), there's other countries with
  other viewpoints of the USA as well that aren't either
  US-centric or Anglo-centric.
  [1]http://www.bbc.co.uk/worldservice/specials/1020_ageofempire/
  Now I'll go back to the torture I was in: I decided I'd get my
  brain around programmable Logic Controllers (PLC) from a
  ground-up perspective - relays to ladder logic, mostly because I
  always looked at circuitry and automation from a computer -->
  machine perspective and it'll be good for me to go in the other
  direction.

References

  Visible links
  1. http://www.bbc.co.uk/worldservice/specials/1020_ageofempire/