On Tuesday, August 12, 2014, another 130 U.S. military personnel arrived in Iraq to help relieve the dire situation of tens of thousands of Yazidi and other Iraqis trapped on a hill by the Islamic State (IS) fighters. These additional troops were not sent to "engage in combat operations."
Their boots are literally on the ground (barring some levitation device that keeps them off the ground). They are armed. They will no doubt be authorized to shoot back at IS fighters if fired upon.
The total of U.S. Security Forces now numbers 875.
Evidently the phrase "boots on the ground" is not to be taken literally so long as the president and the secretary of defense say they are engaged in non-combat operations.