Obama at Pentagon: Diversity One of America's 'Greatest Strengths' to Defeat Terrorists

Obama again referenced the mission to take out bin Laden, praising "the resolve of those Navy SEALS who made sure justice was finally done, who served as we must live as a nation -- getting each other’s backs, looking out for each other, united, one mission, one team."

"...As Americans, we do not give in to fear. We will preserve our freedoms and the way of life that makes us a beacon to the world."

Obama laid a wreath at the Pentagon's 9/11 memorial, joined by Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford and Defense Secretary Ashton Carter.

Carter told the audience that the al-Qaeda hijackers on 9/11 were "motivated by barbarism and hate."

"We need that strength and we have that resolve, as we continue to confront and defeat those who conspired to attack us then – and all who aspire to do so today," he said. "Indeed, when someone strikes at the heart of what we stand for, we respond with the full might of the finest fighting force the world has ever known. Because our memory is long and our reach and resolve are endless, our enemies cannot hide, they cannot escape, they cannot endure. Wherever they are, they will surely, no matter how long it takes, come to feel the righteous fist of American might."