L. Paul Bremer
Following the U.S.-led 2003 invasion, Bremer headed the American occupation government in Iraq until the Iraqi interim government took over in June 2004. In this interview, he discusses the early struggle to build Iraqi security forces, the factors propelling escalating sectarian violence, and the threat posed by Shi'ite cleric Moqtada al-Sadr.

Dexter Filkins
From 2003 to 2006 Filkins reported from Baghdad for The New York Times and won a George Polk Award for his coverage of the Marines' bloody battle in Fallujah in November of 2004.

Abdul Aziz al-Hakim
Shi'ite cleric Abdul Aziz al-Hakim heads the Shi'ite SCIRI party (Supreme Council for Islamic Revolution in Iraq). His party won big in the January 2005 election. He quickly moved to put party members and Shi'ite Badr Corps commanders in key posts. Al-Hakim is the main rival of powerful Shi'ite cleric Moqtada al-Sadr.

Brig. Gen. Karl Horst
From 2005 to 2006, Horst was deputy commanding general of the U.S. Army 3rd Infantry Division, responsible for security in and around Baghdad. He recounts his discovery of a secret Ministry of Interior detention/torture center holding 169 detainees, nearly all Sunni, many tortured. It was another indicator of the extent to which militia forces had infiltrated this key ministry, which is in charge of Iraq's national police.

Bayan Jabr
A top deputy in the Supreme Council for Islamic Revolution in Iraq [SCIRI], a major Shi'ite political party, Jabr was appointed minister of interior after the January 2005 elections. After his appointment, allegations surfaced that the ministry was serving as cover for Shi'a militia forces bent on eliminating Sunni rivals.

Nouri al-Maliki
In April 2006 he became prime minister of Iraq. The leader of the Shi'ite Dawa Party, he rose to power with the backing of powerful Shi'ite cleric Moqtada al-Sadr. He has criticized the U.S.-led coalition for taking military action against the militias and has resisted efforts to go after Moqtada's Shi'ite militia, the Mahdi Army.

Gen. David Petraeus
Currently the top U.S. commander in Iraq, Gen. Petraeus was sent by the Pentagon in mid-2004 to take charge of training Iraqi security forces. Gen. Petraeus talks about challenges he faced back then in coordinating a revamped training system amid growing sectarian violence and insurgent activity, and whether sectarian militias were infiltrating the civilian security forces during that period.

Matthew Sherman
As deputy senior adviser to Iraq's Ministry of Interior from December 2003 to January 2006, Matthew Sherman advised four ministers. He offers a detailed, inside view of the obstacles in building an Iraqi civilian security force that could staunch the escalating insurgency and sectarian violence.