Yeah, I've seen those fictions a lot. But personally I cannot see how those relationships are more solid than the one between America and England even after the special relationship is over or something. I mean, in real world.

Ah, Arthur is a jerk in the fic, but I believe he is actually sad. Well yeah, I know it is just in my wild imagination but I cannot imagine a world where Arthur does not love Alfred TAT

And I am inclined to view "special relationship" as a political relationship, but the personal relationship between the two nation tans are much more and does not build on that.