Geddy Lee explained the genesis of the song in an interview:

The seeds for the song were planted nearly 60 years ago in April 1945 when British and Canadian soldiers liberated the Nazi concentration camp Bergen-Belsen. Lee's mother, Manya (now Mary) Rubenstein, was among the survivors. (His father, Morris Weinrib, was liberated from the Dachau concentration camp a few weeks later.) The whole album "Grace Under Pressure," says Lee, who was born Gary Lee Weinrib, "is about being on the brink and having the courage and strength to survive."

Though "Red Sector A," like much of the album from which it comes, is set in a bleak, apocalyptic future, what Lee calls "the psychology" of the song comes directly from a story his mother told him about the day she was liberated.

I once asked my mother her first thoughts upon being liberated," Lee says during a phone conversation. "She didn't believe [liberation] was possible. She didn't believe that if there was a society outside the camp how they could allow this to exist, so she believed society was done in."[1]