i've come to afghanistan to mark historic moment for the two nations. to do so on afghan soil. i'm here to affirm the bonds. between our countries, to thank american and afghans who sacrificed so much over the last ten years. to look forward to a future of peace and security and greater prosperity for our nations. >> bret: a surprise trip by president obama to afghanistan, signing a new agreement with afghan president hamid karzai talking to troops. and the president will deliver a speech in primetime. 7:30 eastern time. from afghanistan to talk about the end of the war. what he sees it and, of course, this is the anniversary of the killing of usama bin laden.