As former Defense Secretary Donald Rumsfeld says in his new memoir, "Known and Unknown," he is not one for wrestling with remorse. “Never much of a handwringer,” he writes. When Mr. Rumsfeld does share moments of decisionmaking doubt, he tends to emphasize the role that “others” played in leading him or the American public astray. Throughout the memoir, Rumsfeld is not averse to settling some old scores. Here are five mistakes that Rumsfeld acknowledges having made, and the people he wishes would get blamed right along with him.