Two years after US troops departed, Iraqi security forces are struggling to curb violence that has reached a level not seen since 2008, near the height of America's military presence.
Iraqi forces are now alone in facing militant groups revitalised by widespread discontent among the minority Sunni Arab community, which complains of being marginalised and targeted by Shiite-led authorities, and by the brutal war in neighbouring Syria.
They have shortcomings that experts say range from a decline in training and intelligence capabilities to politicisation.
And they no longer have ready access to US expertise, firepower and support that they could fall back on in the past.
Iraqi forces have also been repeatedly accused of carrying out abuses including torture.
Iraq is now hit by daily attacks -- bombs rip through cafes, mosques, markets, weddings and funerals, people are gunned down, and security forces and officials are frequently targeted.
The violence has killed more than 6,500 people since the beginning of 2013, raising questions about the ability of Iraqi forces to secure the country.
"US forces were overseeing or participating or coordinating with the Iraqi forces in their missions before the withdrawal," a senior Iraqi army officer told AFP.
"Iraq is still at the beginning of the road," said the officer, who spoke on condition of anonymity, adding that the US withdrawal "made us take responsibility before we completed filling the shortfall".
The US officially ended combat operations in Iraq in 2010, shifting its focus to training Iraqi forces.
The following year, negotiations on a post-2011 US training mission stalled when Iraq refused to grant US forces legal immunity and Washington declined to keep troops in the country without it.
The last American military personnel, except for a small number under US embassy authority, left Iraq on December 18, 2011.
"One result was that we departed without finishing many basic training goals," said Frank Helmick, a retired US army lieutenant general who served multiple tours in Iraq, including in 2011.
