One key role, that of the Sarkhanese Prime Minister, was filled quite capably by a non-professional, Kukrit Pramoj, a prominent Thai newspaper publisher, former Thai Finance Minister, and, as fate would have it, future Prime Minister (1975-76). Speaking in Bangkok the day after its world premiere, the film's star, Marlon Brando, brought forth gasps by labeling his precocious co-star a "dissembler, liar and thief." Before shock could turn to indignation, Brando, straight face intact, quickly broke the stunned silence. "Mr. Kukrit told me he couldn't act, and then proceeded to prove he could act and, in fact, acted me off the screen. He stole the whole show."
Having previously met then Senator John F. Kennedy, and been particularly "impressed [by] the distinguished cut of his suit," director George Englund had all of Marlon Brando's suits made by the President's personal tailor, Sam Harris.
Two months after the film's release, a syndicated story appeared, entitled "Why Can't the Movie Be More Like the Book," written by one of the source novel's two co-authors, Eugene Burdick. Notwithstanding the article's title and the general critical consensus regarding the film's lack of fidelity to his book, Burdick's own assessment was surprisingly positive. While acknowledging that the film bears "only the most passing resemblance" to his novel, he views this as a plus, seeing 'the picture [a]s better than the book; more integrated, more skillful, and more dramatic," noting that director George Englund and screenwriter Stewart Stern had "crept inside the characters" that he himself "knew only as deeply as ink prints on paper." Moreover, Burdick commends Englund and Stern for "work[ing] much harder than had Lederer and [he]" to flesh out the fictional nation of Sarkhan, while marveling at actor Marlon Brando's ability to inconspicuously "slide into one's mind," then seamlessly integrate the information obtained thereby. Finally, despite noting the myriad changes made to his tale in its journey from printed page to projected image, Burdick can mount only the faintest show of reluctance before conceding that his novel's "political impact is still there."
When Marlon Brando takes a sip of champagne, smiles, and says, "Man, that's coffee," he is alluding to a joke told in the hit play Mary, Mary, by Jean Kerr, which ran on Broadway 1961-64. Mary says she has seen an obviously tired announcer on live TV late at night doing a commercial who took a puff of a cigarette, exhaled, and said, with a big smile, "Man, that's real coffee." The anecdote became well known even to people who had not seen the play and the line was, at the time, used to jokingly praise something that was obviously not coffee.
The film's opening prologue reads, "We are grateful to the people and the tourist organization of Thailand where much of this picture was filmed. The events portrayed, while drawn from recent history, do not reflect the politics or history of Thailand."
In coincidence the event in the film did really happened on the real life, on which U.S. Ambassador to Indonesia Marshall Green experienced the same thing as what Marlon Brando's character Ambassador Harrison Carter MacWhite experienced in the film. Marshall Green who was appointed Ambassador to Indonesia by President Lyndon B. Johnson in June 4, 1965 two years after the movie released, sparking a controversy within Indonesian People who was not welcome his appointment and at some point Indonesian President at that time Soekarno also reluctant to accept Green as U.S. Ambassador to Indonesia. Similar to the event in the film when protester overcome the airport as Ambassador MacWhite arrived, when Marshall Green arrived at Jakarta Kemayoran Airport protester also overcome the airport to protest Green arrival. According to his memoir Green also received unpleasant treat during his first month as ambassador to Indonesia by anti-western movement similar to what happened with MacWhite character in the movie. It would not long until a few months later when the anti-western movement in Indonesia were overthrown, then Green got the more better treatment as U.S. Ambassador to Indonesia.