Former Defense Secretary Robert Gates is releasing his memoir, “Duty: Memoirs of a Secretary at War,” a 600-page book that offers a stark, insider’s view of Washington, the Pentagon, Congress and America’s wars in Afghanistan and Iraq. (You can read an exclusive WSJ excerpt.) Here’s a look at some of the book’s most riveting revelations:

1. Contempt for Congress

Mr. Gates expresses open disdain for Congress and the way lawmakers treated him when he testified at hearings. “I saw most of Congress as uncivil, incompetent at fulfilling their basic constitutional responsibilities (such as timely appropriations), micromanagerial, parochial, hypocritical, egotistical, thin-skinned and prone to put self (and re-election) before country.” Mr. Gates said he fantasized about storming out of hearings and quitting. “There is no son of a bitch in the world who can talk to me like that,” he writes of his fantasy.