Errol Morris must have thought this feature-length interview with former defense secretary Donald Rumsfeld, architect of the Iraq debacle, would generate the same haunting drama as did The Fog of War (2003), his Oscar-winning portrait of Vietnam-era defense secretary Robert MacNamara. But oh my goodness, was he wrong. By the time Morris got to MacNamara, the old man had spent 35 years wrestling with his place in history; here, a mere decade after the botched invasion of Iraq turned into a quagmire that killed nearly 4,500 Americans and some 110,000 Iraqis, Rumsfeld maintains both the avuncular persona of his much-hyped press briefings and his sunny certitude about the second Bush administration’s path in the Persian Gulf. The secretary provides some interesting reminiscences about his early days with the Nixon and Ford administrations, but he cheerily dodges the central question of his role in the greatest U.S. foreign policy disaster of our time. For some people, certain truths are better left unknown.