April 2007 edition of Vanity Fair - The Night of the Generals by David Margolick.

The six retired generals who stepped forward last spring to publicly attack Defense Secretary Donald Rumsfeld's handling of the Iraq war had to overcome a culture of reticence based on civilian control of the military. But while each man acted separately, all shared one experience: a growing outrage over the administration's incompetence, leading some of the nation's finest soldiers to risk their reputations and cross a time-honored line.

By late 2001, briefing Secretary of Defense Donald Rumsfeld was familiar territory for Lieutenant General Greg Newbold. As director of operations on the Joint Chiefs of Staff, Newbold, a three-star in the Marines, had done it many times since Rumsfeld had arrived at the Pentagon earlier in the year, and had come to know the routine: the constant interruptions, the theatrics, the condescension. But, according to Newbold, there was something different, and alarming, about one particular briefing around that time: the topic. It was about going to war with Iraq...
Long article at the link...