Two PoDs:
- Able Archer 83 is butterflied half a year later, so it takes place on late March, ending early April of 1984.
- As an April Fools Day joke intended privately for some technicians before a speech, Ronald Reagan does not realize that the microphones are on and the cameras running when on April 1 of 1984 he speaks the words "My fellow Americans, I'm pleased to tell you today that I've signed legislation that will outlaw Russia forever. We begin bombing in five minutes." (IOTL, this was spoken in August of that year, and was not broadcast live.)
The world dies in nuclear holocaust within hours. The few (if any) American survivors can console themselves with the knowledge that the Russians started it.