The year was half over when, while accepting his nomination for a record fourth presidential term, FDR asked the question, “What is the job before us in 1944?” His answer–first, win the war–may seem obvious, but Jay Winik’s new book, 1944: FDR and the Year That Changed History, suggests he missed a step. There was a chance to slow the Nazi killing machine, Winik argues, by bombing the rail line to Auschwitz rather than leaving liberation for after the fight. But Roosevelt didn’t, and therein lies the history-shifting rub.
Nimbly toggling between hemispheres, Winik knits familiar WW II headlines with surprising details from leaders’ lives, though the highlighting of FDR-Hitler coincidences can have the jarring feel of a Kennedy-Lincoln conspiracy theory. His recounting of concentration-camp logistics is haunting, and the tales of those who tried desperately to stop the mass murder have cinematic force.
The story in Washington feels slower, which is fitting. In 1944, through D-Day and an election, the once energetic Roosevelt grew weaker. He wouldn’t live to see the camps, the bodies, the truth he had known but perhaps never fully grasped. He had no time to regret forgoing his “Emancipation Proclamation moment” by allowing Auschwitz to stand one day longer than it had to.
Winik likes to write about specific time periods, as he also did in his 2001 best seller April 1865. The genre is built to ask whether this single year was truly singular. So did history change in 1944? Yes.
Winik’s vision of an alternate universe–in which an earlier end to Auschwitz creates a world that prizes goodness–is hard to buy yet easy to crave. But opportunities to demonstrate humanity are frequent, and there’s no reason history can’t change the future.
This appears in the October 05, 2015 issue of TIME.