Washington (CNN) -- The Department of Defense recently purchased and destroyed thousands of copies of an Army Reserve officer's memoir in an effort to safeguard state secrets, a spokeswoman said Saturday.
"DoD decided to purchase copies of the first printing because they contained information which could cause damage to national security," Pentagon spokeswoman Lt. Col. April Cunningham said.
In a statement to CNN, Cunningham said defense officials observed the September 20 destruction of about 9,500 copies of Army Reserve Lt. Col. Anthony Shaffer's new memoir "Operation Dark Heart."
Shaffer says he was notified Friday about the Pentagon's purchase.
"The whole premise smacks of retaliation," Shaffer told CNN on Saturday. "Someone buying 10,000 books to suppress a story in this digital age is ludicrous."