A U.S. soldier arrives to the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus)

Photo by: Anja Niedringhaus

A U.S. soldier arrives to the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus)