i'm going to look really stupid for asking this
so this takes place during the cold war? which was when?
and did the UK actually get attacked?
please forgive me, but i was only 6 years old in 1991 when wikipedia says this war ended.
The cold war ended without any nuclear confrontation. What you see in this film is what would have happened if tensions has escalated, which in the 80s they treatened to do at times.
But nope, the only country to suffer an actual nuclear attack was Japan in 1945.