When Americans asked, " Why do they hate us? " as the ashes were still smoldering last September, they seemed to voice an innocence that was being lost. Perhaps it is this very innocence that so much of the world hates.

This is the issue raised by The Quiet American, a new film starring Michael Caine and Brendan Fraser, based on Graham Greene’s incendiary 1955 novel about a young, idealistic CIA agent who colludes in the bombing of a public square in Saigon.

Miramax Films first screened a rough cut of the $22 million movie to an enthusiastic audience last September 10. But the world was a different place in the months afterward, and test responses showed audiences were unhappy with the film’s harsh indictment of American conduct abroad. Now, with the film’s world premiere this week at the Toronto Film Festival, Australian director Phillip Noyce hopes that Americans are ready to embrace its tough questions.

" Up until last New Year, there was a raw wound in the American psyche, and I think that wound has healed with time, " Noyce says.

Set during the Indochina War between the French colonialists and the Vietnamese, The Quiet American centers on a love triangle involving Fowler, a world-weary, opium-addicted British correspondent played by Caine, his Vietnamese mistress Phuong, and Pyle, the fresh-faced American who befriends Fowler and becomes Phuong’s new lover.

An operative posing as an aid worker, Pyle arranges the Saigon bombing, which kills dozens of women and children, because he believes in offering the Vietnamese a " third force " — a democratic alternative to the French imperialists and the Communists.

Greene was hailed for his prescience a decade later, when the interventionist policy that his novel eviscerates developed into the American war in Vietnam.

According to Noyce, the film’s most sensitive aspect is that it asks the audience to accept Fowler’s decision to betray his friend Pyle to the Communists, and thus, in effect, the judgment that the American deserves to die for perpetrating a war crime. The more disturbing implication is that, through its critical portrayal of Fowler, the film may serve to explain or justify the rage that has prompted recent attacks against the US.

Noyce suggests that Americans are grappling with essentially the same dilemma today as they were at the onset of the Cold War: as a superpower and melting pot, the United States may be forced to take responsibility for the troubles of the world, but when does that justify meddling in the affairs of sovereign nations?

" I think [Greene’s] point is that sometimes trying to do the right thing can get you into more trouble than trying to do the wrong thing, " the director says.

The novel set off a furor when it was first released, with Newsweek charging that Greene had created cardboard characters that the Soviets were happy to turn into propaganda fodder. The Hollywood adaptation — directed by Joseph Mankiewicz in 1957, during the height of McCarthyism — changed the ending to portray Pyle as guiltless, and Fowler as the beast for betraying him.

Gene Phillips, author of Graham Greene: The Films of his Fiction, said Greene was indeed a hard-line lefty, who by his own admission spied for Fidel Castro and hobnobbed with Manuel Noriega. But his novels are rich with complexity and contradiction, and it does him a disservice to read his fiction too simply.

" I think Greene’s main virtue is always telling a good story, " Phillips says. " You get caught up in the story of The Quiet American, and it’s not a talk piece, where you are just analyzing politics. You get swept up in the melodrama of it. "

The Quiet American screens at the Boston Film Festival Friday, September 13 at 7 and 9:15 p.m., and Saturday, September 14, at 11:45 a.m., 2, and 4:15 p.m.

To read a transcript of Julien Gorbach’s interview with The Quiet American director Phillip Noyce and Graham Greene biographer Gene Phillips, visit www.juliengorbach.com