In the 2003 DVD commentary, Alan Arkin relates that Marlon Brando once told him he had seen this film 20 times and even imitated Arkin's delivery of certain lines from the film. Writer Andrew Bergman concurs that Brando's appreciation of his script was integral to getting Brando to star in The Freshman (1990).
When Vince is getting directions to meet the general, the streets include "United Fruit Boulevard," a reference to the US company that historically dominated much of Central America--economically and politically--and gave rise to the expression "a banana republic."
Decades before Peter Falk played the part of a CIA agent, and well before he decided to become an actor, he applied for a job at the CIA (during the "Red Scare" era brought about by Joseph McCarthy). Falk managed to get an interview with the agency, but his interviewer told him that one of the schools he went to, the New School for Social Research, had a "pinkish" reputation, and that because Falk once was a member of the "communist-dominated" Marine Cooks and Stewards Union, he not only couldn't work for the CIA, but wouldn't find work anywhere in Washington.