It is a rewrite of a famous quote by Winston Churchill, the great English
Prime Minister that was able to successfully drive England out
of WWII and to win other Nazi Germany and Italian Fascism.
The quote goes like this:
“Soviet Union foreign policy is a puzzle inside a riddle
wrapped in an enigma, and the key is Russian nationalism.”
I don't know the year, should have been around 1940;
The meaning: something with an unpredictable behaviour, that does not follow
an easy way of definition; I think this is mostly applied to a human being;
Regardless ABC: not considering ABC, not taking in account the influence, the opinion of ABC