As today's live broadcast begins, President Obama is addressing national security at the National Defense University in Washington. In a lengthy briefing prior to the speech, aides outlined his renewed intention to close the prison at Guantánamo Bay and his plans to establish new rules for the use of unmanned drones for targeted killings. The President said that, while terrorism is a threat that will always be with us, it's not a reason for perpetual war. With US troops leaving Afghanistan, and al Qaeda leadership decimated since the attacks of September 11, he said it's time to refocus American strategy. Will today's speech win support from a divided Congress?