YA book, girl discovers portal(?) to alt reality where the Cuban missile crisis(?)?happened
I would have read this around 2008-2013, the plot was something about a girl finding out she could travel to another reality where the Cuban Missile Crisis actually happened and the US is a dystopia. She had a male friend in her normal timeline and then met a love interest in the apocalypse timeline, I think it was a love triangle. She had to choose between staying home or helping the new boy.
u/hannahdablomb — 3 days ago