Obama accepts Nobel Prize in Oslo

President Obama delivers his Nobel lecture at the Nobel Peace Prize award ceremony at Oslo City Hall on Thursday. The president faces the tricky task of reconciling the revered honor with his decision just last week to send 30,000 troops to escalate the war in Afghanistan, a move which tripled the U.S. force there since he took office. (Oliver Morin AFP / Getty Images)

Sept. 16, 2014 6:47 PM PT

The chairman of the Norwegian Nobel Committee, Thorbjoern Jagland, with blue tie, arrives with Norway’s King Harald at his right for the Nobel Peace Prize award ceremony at the City Hall in Oslo on Thursday. (Oliver Morin / AFP / Getty Images)

Climate protesters gather outside Oslo City Hall as President Obama receives the Nobel Peace Prize. Obama accepted the prize, saying he was humbled by the award and received it with an “acute sense” of the cost of war. (Chris Jackson / Getty Images)

President and Nobel Peace Prize laureate Barack Obama jokes with the chairman of the Norwegian Nobel Committee, Thorbjoern Jagland, after giving his Nobel lecture at the Nobel Peace Prize award ceremony at City Hall in Oslo. (Oliver Morin AFP / Getty Images)

The 2009 Nobel Peace Prize laureate, President Obama, with his diploma and gold medal during the Nobel ceremony at the City Hall in Oslo. (Jewel Samad AFP / Getty Images)

Actor Will Smith and his wife, Jada Pinkett Smith, sit with their daughter Willow during the Nobel Peace Prize award ceremony at City Hall in Oslo. (Jewel Samad / AFP / Getty Images)