The US troop surge in 2007 helped quiet Iraq's bloody civil war. But it failed to deliver on what US officials and officers said was crucial for Iraq's future at the time: sectarian reconciliation. Rather than forging a new national identity out of the horrors of Iraq's war, Iraq's Shiite and Sunni Arabs and ethnic Kurds sullenly retreated to their own sectarian corners, and the country's political parties remain vehicles for ethnic or sectarian interests. The next year is probably going to be the most crucial for determining the future of Iraq since the US-led invasion of 2003, as Iraq's various political factions compete for power and influence without foreign troops getting in the way. Here are a few of the major players.
Al Qaeda in Iraq, the group responsible for many of the deadliest attacks in the Iraq war, claimed responsibility for last week's bombings in Baghdad that killed 69.
The death toll in a string of attacks in Baghdad, mostly against government and Shiite targets, is up to 68. The attacks follow days of political threats against Sunni politicians by Shiite Prime Minister Nouri al-Maliki.
A trawl through US diplomatic cables released by Wikileaks this year shows growing alarm over Iraq's political divides.
Deadly Baghdad bombings today, which followed an arrest warrant for a top Sunni official, comes just days after the final US troops left the country.
The scars of Iraq's painful bloodletting are deep, and a powerful disincentive against a return to open warfare. But Shiite Prime Minister Nouri al-Maliki is moving against Sunni Arabs, his political enemies.
Camp Ashraf, home to militants opposed to the Iran regime who are also unpopular in Iraq, faces year-end closure. Some fear there could be violence and even suicide, but there are signs of a negotiated settlement.
The US government is close to wrapping up its case against Army Pfc. Bradley Manning, accused of providing classified documents to WikiLeaks.
The cost of the Iraq war was high, in lives and treasure. Families who lost loved ones can take heart that Saddam Hussein, one of the worst dictators since Hitler, is gone. But the final answer to whether this US effort was worth it still awaits history.