Survivors recount the horrors they endured on 9/11. Immediately after the attacks, George W. Bush begins charting America's aggressive military response.
Learning the hijackers benefited from the gaps in US intelligence, the White House justifies a secret surveillance program and "enhanced interrogation".
With no cohesive strategy, the war in Afghanistan squanders early successes and backfires, fueling disillusionment, corruption and a Taliban resurgence.
