The Pentagon has burned 9,500 copies of Army Reserve Lt. Col. Anthony Shaffer's memoir "Operation Dark Heart," his book about going undercover in Afghanistan.
A Department of Defense official tells Fox News that the department purchased copies of the first printing because they contained information which could cause damage to national security.
The U.S. Army originally cleared the book for release.
The U.S. Defense Intelligence Agency attempted to block the book about the tipping point in Afghanistan and a controversial pre-9/11 data mining project called "Able Danger."
In a letter obtained by Fox News, the DIA says national security could be breached if "Operation Dark Heart" is published in its current form. The agency also attempted to block key portions of the book that claim "Able Danger" successfully identified hijacker Mohammed Atta as a threat to the United States before the Sept. 11, 2001, terror attacks.