THEY don't call it perfidious Albion for nothing, and likewise there is a reason why Spanish speakers use the expression “hijo de la Gran Bretaña” (son of Great Britain) in much the same way and with much the same meaning as the English term "son of a b****.
It is because Britain has a reputation abroad for being untrustworthy, underhand and duplicitous in its dealings with other countries. The British nationalist self-image of Britain being characterised by fair play and incorruptibility is a fantasy that is not shared by anyone else.
