* Rumsfeld sticks to guns, documentary maker says
* "Unknown Known" one of two documentaries in Venice
* Director Morris says lets people hang with own words
Errol Morris is not at all certain why former U.S. Secretary of Defense Donald Rumsfeld agreed to let him make a documentary portrait of the man who oversaw the Iraq and Afghanistan invasions, but he is convinced of at least one thing.
Rumsfeld, he said, has no regrets about the campaigns.
"Rumsfeld never came even close to calling these wars a mistake, an error of judgment, let alone saying 'I am sorry'," Morris told Reuters on Thursday after the screening of his film "The Unknown Known" at the Venice Film Festival.
Rumsfeld may have expected to receive something less than a sympathetic hearing from the film maker. Both the Afghan and Iraqi wars stirred controversy over their conception and conduct. Critics have focused often on the figure of Rumsfeld, who argues that he took necessary action in a time of crisis.
Morris's film takes its title from a famous Rumsfeld dictum about what is known and what is not known, the uncertainties of intelligence. It is one of an unprecedented two documentaries in competition for the Golden Lion trophy for best picture to be awarded on Saturday night.
Asked why Rumsfeld, who had a deeply combative relationship with the press, agreed to make the film, when a lawyer for Rumsfeld had assured Morris he would not, the filmmaker said: "I don't think there are simple answers to those 'why' questions.
"Why did he agree to talk to me, why did he agree to make the movie?" Morris offered no answer to his own questions, although he had won an Oscar for his 2003 documentary "The Fog of War" about Vietnam-war era defense secretary Robert McNamara.
Rumsfeld never opened up to him the way McNamara did, Morris said, even though McNamara also never apologised, on film, for the Vietnam War, and its nearly 60,000 American war casualties.
Under Rumsfeld's tenure as defense secretary in the George W. Bush administration, the United States invaded Afghanistan to punish the Taliban for harbouring al-Qaeda and the 9/11 attack mastermind Osama bin Laden. The United States then led a coalition that invaded Iraq.
Over 4,000 U.S. service personnel were killed in the Iraq war. Saddam Hussein, a dictator with a record of brutal rule, was overthrown, but invading powers failed to find the weapons of mass destruction they had expected.
Morris, who has run into criticism at Venice that he did not seem to pepper Rumsfeld, who is 81, with tough questions, said he did not see it as his role to create a "kind of passion play where I'm the priest and my subject is in confession".
He said his portrait of the man who served in three U.S. administrations showed a "different kind of story" than what would have come out by taking a confrontational stance.
"To say that there are no difficult questions being asked in this movie is only to say that the movie works on a different principle than what we normally expect," Morris said.
"It's not somebody confronting him and shaking him by the shoulders trying to get him, 'Okay now sir, admit all of it, say you were wrong.'
"Instead, and it's part of what I do, if I'm going to be an executioner I prefer to have people hung with their own words."