An engrossing and illuminating documentary, The Fog Of War provides, as its stodgy subtitle explains, "11 Lessons From The Life Of Robert McNamara." Which doesn't sound very thrilling, but the reflections of the former US Secretary of Defence provide a window into the moral reasoning of a brilliantly-minded manager who became a self-declared "war criminal". A man who, at the behest of president Lyndon B Johnson, mired America in the Vietnam War, contributing to the deaths of 58,000 US soldiers and 3.4 million Vietnamese.

"My rule has been to try to learn, try to understand what happened. Learn the lessons and pass them on," he says, talking straight to camera as veteran documentary-maker Errol Morris probes and pokes. There are no great revelations, no conspiracy theories unpicked, but the slick self-justification of this charismatic 80-year-old is quietly devastating, as he claims that "In order to do good you may have to engage in evil" (lesson nine), or "You can't change human nature" (lesson 11).

"MORRIS ILLUMINATES AN ERA"

His first experience of doling out Death came in World War Two, when he was partly responsible for the firebombing of Japan. Even apart from the use of nuclear weapons of mass destruction on Hiroshima and Nagasaki, the devastation was appalling. There's a sequence showing the percentage of each Japanese city destroyed, then naming their American counterparts (Tokyo equates to New York; 51% was obliterated). Statistics have never been so shattering. McNamara cries as he remembers that he learned "Proportionality should be a guideline in war" (lesson five).

Post-war he was the first non-family member to preside over Ford Motors, but after five weeks President Kennedy appointed him to Defence and they set about withdrawing from 'Nam. Then - pop - JFK was dead; LBJ ordered the boys back in and McNamara did as he was told.

Taking a lucid, non-sensationalist approach, Morris illuminates an era, without drawing attention to himself or massaging a message out of the material. Still, when LBJ states, "America wins the wars that she undertakes and we have declared war on tyranny and aggression," it sounds terribly familiar.