Five years after Barack Obama announced that that "war in Iraq ends this month”, at least 5,000 American military personnel are currently stationed in the middle eastern country.
Following the president's decree, the last US troops withdrew a week before the Christmas of 2011. But after Isis gained significant territory in the country three years later, the US was forced to put boots back on the ground.
Although many are presented as advisors to the Iraqi forces, US military personnel are reportedly able to call in air-strikes and artillery fire, as well as influencing troop movements on the ground.
The number of US troops has increased in recent months in anticipation of an attempt to seize the city of Mosul from Isis. The city in nothern Iraq is the group's last major stronghold in the country.
The US has ploughed $10bn (£8bn) into the intervention since it returned to the country to fight the terror group and outgoing US secretary of defense Ash Carter said earlier in this month that it was “certainly possible” that Mosul could fall before Donald Trump enters the White House on 20 January.
But the deputy commander of the US coalition in the region, Major General Rupert Jones, has called for “patience”, saying more time was needed to minimise the danger to civilians.
However, the President-elect has expressed impatience with that strategy and promised to eliminate the group quickly when he takes office.
He said that he would attack the militants harder than his predecessor, by bombing “the shit out of ‘em”.
But according to the Pentagon, the US has carried out over 7,000, or three quarters, of the airstrikes in the country.
Between the invasion of Iraq in March 2003 until the end of 2011, around one million US military personnel were deployed in the country. The conflict claimed the lives of 4,486 and more than 32,000 were wounded.
Hundreds of thousands of Iraqis died during the invasion and subsequent war, though estimates of the true total vary.
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