Much of what you know about Donald Rumsfeld is wrong. I know, because I worked intimately with him for four years, from the summer of 2001 until I left the Pentagon in August 2005. Through countless meetings and private conversations, I came to learn his traits, frame of mind and principles ? characteristics wholly at odds with the standard public depiction of Rumsfeld, particularly now that he has stepped down after a long, turbulent tenure as defense secretary, a casualty of our toxic political climate. I want to set the record straight: Don Rumsfeld is not an ideologue. He did...