Jake Black just wants to play baseball.
As he wiles away the summer of 1953 in the Minors, beer and sun help him ease memories of Isaak, the brother he lost in the War. When Army Intelligence wants him back, Jake’s not interested - until they tell him that President Taft has terminal cancer, and maybe Isaak is not dead after all.
The mission is simple: coach the Embassy team in Tehran while ensuring the CIA doesn't botch their first ever coup attempt. Jake discovers Iran on the verge of civil war. After a crash course in Persian and hookah smoking, he tracks Kim Roosevelt, Middle East Station Chief, by day and combs the expatriate bars at night for signs of Isaak. Demonstrations soon become riots as Jake mixes with communist insurgents, Polish refugees, British journalists, striking oil
workers, and anyone who can hit a fastball. Can he find his brother and keep the country from crumbling into chaos before Vice President MacArthur sends in the paratroopers?
Tehran Summer is an alternate history spy thriller.
The most essential thing in "alternate history" is that you tell us what event did/didn't happen that makes this the alternate. Philip Roth did this with The Plot Against America: FDR doesn't win the election in 44.
What you're missing here is the event that makes me understand why Taft is president in 53 and not dead. Without that, this is just events without context.