The backstory thing is weird.
What I always find funny is how people agonise over the premise and background for a postapocalyptic game.
Having a clue who you're fighting, why you were fighting, and for how long you have been fighting informs who you are, what you're equipped with, and whether you're trying to go somewhere or stay nearby.
It's not like a zombie plague where there's nowhere to get to that's really better than where you are, save by being more wild than urban.
Portions of the setting are still largely intact... not parts near the start point in polands...
Additionally, the setting backstory explains where alternate start points can be while sharing the setting. Knowing that it's Soviet Block vs NATO means one side is all slavic speaking - even if its not the mother tongue for many of the soldiers. Meanwhile, the NATO side will have most speaking some English... but knowing Polish, German, or Ukrainian can be of use outside of combat.
Part of the appeal of T2K is that it was, when written, a plausible (if unlikely) future. Part of it still is that we know bits about the real cultures there, and can break out the real maps, and some of us have been to the real places... which necessitates know where one is.