Former Secretary of State Colin Powell during his appearance Sunday on CBS News' Face the Nation. Chris Usher/CBS News via Getty Images hide caption

itoggle caption Chris Usher/CBS News via Getty Images

An Afghan boy stands aside a motorbike used by a suicide bomber in Kandahar City on Oct. 23. Two civilians were killed and two others were wounded in the attack. Rahmat Gul/AP hide caption

itoggle caption Rahmat Gul/AP