Barack Obama

Barack Obama

President Barack Obama waves as he arrives to speak at the memorial service for former South African president Nelson Mandela at the FNB Stadium in Soweto, South Africa Tuesday, Dec. 10, 2013. (AP Photo/Evan Vucci)

President Barack Obama waves as he arrives to speak at the memorial service for former South African president Nelson Mandela at the FNB Stadium in the Johannesburg, South Africa township of Soweto, Tuesday, Dec. 10, 2013. World leaders, celebrities, and citizens from all walks of life gathered on Tuesday to pay respects during a memorial service for the former South African president and anti-apartheid icon. (AP Photo/Evan Vucci)