Does nationality help?

What role is played by your "national interests" in reading/appreciating a book?
What role is played by your understanding of the country's history, knowledge of current affairs etc?
Does the book's setting make a difference?

These ideas occurred to me while I was trying to fathom why I didn't like THE DELICATE STORM as much as those who gave it the 2004 Arthur Ellis Award (from the Crime Writers of Canada) - but then is that award only for Canadian writers?
I've almost decided that the answer lies in the fact that the murder mystery was so deeply entangled with Canadian political history and other facts such as the relationship between law enforcement agencies in Canada itself, and between the USA and Canada.

You might think my questions have rather obvious answers, but I think they also have something to do with writing style, reading traditions and so on.
For example, my reading of choice is almost without doubt (how's that for hedging your bets?) British crime fiction. I think that has a lot to do with the fact that I was brought up on British literature, and that the crime fiction most readily available in Australia was British. I remember very clearly when the paperback became readily available in Australia and I began devouring Agatha Christie in particular. Mind you I also devoured Simenon, so perhaps my argument doesn't hold much water.