In keeping with Barack Obama's presidential campaign promise, the US withdrew the last of its combat troops from Iraq in December 2011. ln the first of a two-part series, Fault Lines travels across Iraq to take the pulse of a country and its people after nine years of foreign occupation and nation-building. Now that US troops have left, how are Iraqis overcoming the legacy of violence and toxic remains of the US-led occupation, and the sectarian war it ignited? Is the country on the brink of irreparable fragmentation? Can the ghosts of the past ever stop haunting the future? Correspondent Sebastian Walker first went to Baghdad in June 2003 and spent the next several years reporting unembedded from Iraq. In part 1, he returns and travels from Basra to Baghdad to find out what kind of future Iraqis are forging for themselves.