President Obama delivers his speech to the Nunn-Lugar Cooperative Threat Reduction (CTR) symposium at the National Defense University in Washington on Dec. 3, 2012. Seated are (from left) Defense Secretary Leon Panetta and Sens. Sam Nunn and Richard Lugar. (Associated Press)

Photo by: Manuel Balce Ceneta

President Obama delivers his speech to the Nunn-Lugar Cooperative Threat Reduction (CTR) symposium at the National Defense University in Washington on Dec. 3, 2012. Seated are (from left) Defense Secretary Leon Panetta and Sens. Sam Nunn and Richard Lugar. (Associated Press)