The War/Veterans
War? What War?
Even though World War II is less than a decade behind Marty'smodern day, it's only mentioned twice: First, when Clara's blind date says that he'll introduce Marty as his "army buddy," and second, when Marty tells Clara about his life after the war.
While the first mention is fleeting—maybe just a reminder that most men around Marty's age are vets, too—the second does a lot of explaining about who Marty is and how he got that way. When he got back from the war, he tells Clara over that untouched pie, he felt like he had lost step with everybody else. He didn't sleep, couldn't find a job, and even thought of suicide… which he acknowledges is a key sin for a Catholic like him.
Of course, a family friend finally offered Marty a job at the butcher's shop, and there he's stayed, as if dropped there (unlike the actor who plays him, who took advantage of the GI Bill and went on to be a star).
It makes us wonder if the movie seems to be saying something about the fate of Marty's generation, and how fighting for his country disrupted an otherwise straightforward family-driven life. WWII is like a kind of global ghost narrative, lurking spookily underneath Marty's family drama and love story.