Errol Morris.("The Fog of War")

As a student at the University of Wisconsin in the late 1960s, documentary filmmaker Errol Morris demonstrated against the Vietnam War, and in particular the U.S. secretary of Defense, Robert McNamara. Under John F. Kennedy McNamara had defused the Cuban missile crisis and persuaded the president to withdraw from Vietnam. Then Kennedy was assassinated and McNamara, who stayed on under President Lyndon Johnson, implemented the escalation of the Vietnam War. A decade ago, in his memoir "In Retrospect," McNamara confessed the decision to wage war in Vietnam was "terribly wrong." Morris was intrigued. Known for his tough interviewing in films like "The Thin Blue Line," he recently directed a new, devastatingly frank documentary about McNamara, "The Fog of War." The film, which opens in Europe this week, is startlingly prescient and has already won several U.S. awards. NEWSWEEK's Dana Thomas recently spoke to Morris. Excerpts:

What do you hope to achieve with this movie?

I suppose I wanted to make an antiwar film. I don't like antiwar films that tell us the obvious: that war is bad. I wanted to tell a much more specific story about conflict--about people blundering into wars, about people having to make decisions based on expedience that will carry enormous ethical weight. I am interested in certain ironies--like the fact that he's talking about 40, 60 years ago, and for all intents and purposes he could be talking about last week. There is something horrific about the idea that nothing really has changed.

Did you think the film would be so relevant to what's going on today?

Not really. I started it before September 11. But it is becoming more topical day by day, particularly the notion of "preventative war." McNamara's first childhood memory is of Armistice Day, the war that Wilson described as "the war to end all wars," the ultimate preventative war. And what followed? The worst carnage known to man. War doesn't prevent war. War leads to more war. And if we have not learned that from the past, I don't know what will teach us.

How do you see McNamara in the context of American history?

He's like Zelig, only he wasn't just a peripheral character who shows up at opportune historical moments. He's actually an important figure. And he's in all of these moments--he's even there with Jackie, looking for a gravesite for JFK.