The U.S. military is requesting authority to send up to 500 new troops to Iraq ahead of a much-anticipated campaign to take back Mosul from Islamic State, according to U.S. officials, adding to an expanding American presence in the country.
The new deployment, if approved by the White House, would assist Iraqi and coalition forces in preparing for the battle to capture the northern city, the extremist group’s last major stronghold in Iraq. That fight is expected to begin as early as mid-October, U.S. officials have said.
The U.S. move would come in the wake of an operation that began Tuesday by Iraqi forces in Shirqat, a town north of Baghdad, to further degrade Islamic State supply lines into Mosul. That operation, which was announced by Iraqi Prime Minister Haider al-Abadi in New York, where he is participating in U.N. General Assembly meetings, is a further indication that the Iraqi forces are preparing for the larger fight in Mosul, a city of about one million people.
The new U.S. forces would increase the number of American personnel officially deployed to Iraq from 4,400 to about 4,900. The Pentagon also maintains up to 1,500 additional U.S. forces that it doesn’t acknowledge as part of its Iraq force, most at the U.S. Embassy in Baghdad or on temporary assignments. The new deployment would bring the overall U.S. presence to as high as 6,400. The 500 would be in addition to roughly 400 new personnel the U.S. sent to Iraq in early September to prepare for the Mosul offensive.
President Barack Obama hasn’t yet been presented with the military plan, according to U.S. officials.
The White House maintains that the troops the Pentagon sends to Iraq aren’t heading into direct combat. Rather, U.S. officials have said, those troops are there in an advise-and-assist mission. While they are armed and always have the authority to defend themselves on the battlefield, they aren’t performing direct action missions, officials have said repeatedly.
Advise-and-assist forces operate under instructions to remain “one terrain feature” behind any battle, meaning they must stay some distance behind the front lines of fighting and serve only in an advisory role. However, there have been instances in which U.S. troops have been killed or injured while operating under these strict guidelines.
Most of the new troops would be assigned to an area the U.S. military has established south of Mosul at a logistics hub known as “Q-West” near the city of Qayara. Hundreds of U.S. and coalition forces have massed there in the past several months in anticipation of the Mosul fight.
The same base was the target this week of what U.S. officials said was a rocket or mortar fired by Islamic State fighters, and containing a mustard agent, into the perimeter of the base where U.S. service members are deployed, senior defense officials confirmed Wednesday. The weapon was described as “crude” and ineffective.
No U.S. personnel were injured in the Tuesday attack. But the incident marked the first time Islamic State had deployed a weapon containing a mustard agent against U.S. forces, defense officials said. The attack resulted in no change in security posture, defense officials said. Islamic State has used weapons with a mustard agent about two dozen times. They typically have been used against Iraqi or Peshmerga forces or Iraqi civilians, officials said.
The fight for Mosul—seen as the biggest battle yet against Islamic State—has been delayed for more than a year. The U.S. military has hinted at different times the effort would begin. Mr. Abadi recently has signaled he wants the city taken by the end of the year.
In recent months, U.S. officials also have said that the Iraqi military appears ready to take the lead in the fight and as recently as two weeks ago said they expected Iraqi and coalition forces to enter the city sometime in October.
U.S. military officials have said it is unclear what kind of fight they will find once inside Mosul. Gen. Joe Votel, who heads U.S. Central Command, said last month there may be areas Islamic State decides to cede to coalition forces immediately, and others in which it decides to fight to the death.
“They are going to have to make hard decisions about where they’re going to concentrate their power and where they’re going to have to let the coalition and our indigenous partners succeed, and that’s kind of what I see going forward,” Gen. Votel said at the Pentagon on Aug. 30.
Separately, the White House is considering steps in Syria to more directly arm the Kurdish forces it has been supporting there. That decision would help to focus the so-called YPG, which may be the primary force behind the retaking of the Islamic State stronghold of Raqqa, the de facto capital of the militant group’s caliphate.
U.S. officials have been discussing ways to help prepare the YPG for that fight, and the YPG has sought more direct assistance from Washington in the form of more small arms, ammunition and possibly some non-lethal assistance like trucks or medical equipment.
Up until now, the U.S. has only indirectly armed Kurdish forces, seen as the most effective in the fight against Islamic State, by equipping the Syrian Democratic Forces, which include Arabs who are closely aligned with Kurdish forces. The U.S. has provided numerous ammunition drops to the SDF as a fig leaf for its quieter support of the Kurds there, U.S. officials have said.
The move likely would anger Turkey, which believes the Kurds seek a semi-autonomous state along its border inside Syria and equates military assistance to the YPG with helping the Kurds take a step closer to that end.