Rafe is clearly British so how the hell is he accepted into the FBI, i thought they don't accept foreigners?
There is a possibility that he was born in America to british parents...:)
Gabe asked Jake about that shortly after they arrived on the island. Jake said something like him being 100% American on the inside.
Except that still doesn't answer the issue of him being 100% NOT American on the outside.
It's because Will Kemp can barely act, let alone attempt an accent.