I admit I clicked nearly on the Back-button right at the beginning when I stared in horror at the "Spring Break"! Which of course doesn't exist in GB. One of my serious squicks is American culture (It's somehow always US-Americans who do this, at least in my experience - I'm sure I'd find it just as annoying if other nationalities were just as prone to force their own customs onto other countries in fanfiction.) transplanted randomly into other cultures out of ignorance or for other reasons.
I'm glad I decided to read on though! ^_^ It was very enjoyable and the world-building was really well-done. The somewhat open ending fit quite well here imo. The fleshing out of some supporting characters with just a few sentences was impressive, especially that of unsympathetic ones like McNair: many writers make the bad characters complete monsters without a single redeemable feature or impulse, which isn't very realistic imo.