During Afghan war, lack of U.S. knowledge yielded a flawed strategy

For nearly two decades, the United States' military engagement in Afghanistan has been plagued by strategic missteps, according to The Washington Post's bombshell report. The investigation examined thousands of pages of previously unpublished notes and interviews from the U.S. government's Lessons Learned project analyzing the war. Nick Schifrin talks to retired Army Lt. Gen. Douglas Lute.