President Obama insists he will not have “boots on the ground” in the fight against the Islamic State of Iraq and Syria (ISIS), but the line between a combat and advisory role is blurry.
Obama plans to send more than 1,600 troops to Iraq as “advisers” to the military, and all of them could find themselves in harm's way.
Several hundred more troops will work closely with Iraqi and Kurdish forces to train and advise them about how to fight ISIS on the ground.
Other troops will serve in support roles, including 200 soldiers from the 1st Infantry Division who will deploy in late October to Baghdad and Erbil.
The support troops include operations planners, and intelligence, logistics, and communications specialists.
The deployments have alarmed members of Congress, with some raising comparisons to Vietnam, when a prolonged military conflict began with deployments of advisers.
Obama has rejected concerns about “mission creep,” and has placed U.S. forces under strict orders not to accompany Iraqi forces on operations where contact with ISIS is intended, expected or likely, according to a source familiar with the troops' missions.
Experts say the troops are in harm's way.
"There are no 'front lines' in wars today," said Jim Carafano, the Heritage Foundation's Vice President for Foreign and Defense Policy Studies and a 25-year Army veteran.
"These guys are going to use terrorism in the country as part of their campaign," Carafano said. "They will try to kidnap U.S. troops, behead them, kill them."
ISIS has already threatened to advance towards Baghdad, prompting the president to order U.S. troops to secure diplomatic facilities and property in June, and then airstrikes in August.
The U.S. has conducted more than 200 airstrikes since then, which have been conducted increasingly closer to Baghdad.
Military officials say they expect ISIS fighters to adapt to the airstrikes by dispersing into the cities, where they might be harder to find.
Already, there are reports of ISIS attacks inside Baghdad, where the majority of U.S. troops inside Iraq are stationed.
"In a war without front lines, all soldiers are potentially in combat," said Daniel R. Green, defense fellow at the Washington Institute and Navy reservist who served six months in Fallujah in 2007.
Green said Al Qaeda in Iraq, which is now considered ISIS, would do complex attacks in cities such as Fallujah, using car and truck bombs, followed up by small arms fire.
"It's hard to say, 'Well, these forces are on bases, they're behind the wire.' But they're definitely exposed to risk."
Military officials have already said they could recommend having U.S. troops ride along for combat missions with Iraqi and Kurdish forces in the future.
"At some point, if we have to advise them more closely than currently we are, of course, I'd recommend it. But we haven't reached that point," Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey told reporters at a briefing on Friday.
Even if Americans avoid the battlefield, U.S. troops training Iraqi and Kurdish forces would be at risk for "green on blue" attacks where forces being trained attack their mentors, Carafano said.
Defense Secretary Chuck HagelChuck HagelWho will temper Trump after he takes office? Hagel: I’m ‘encouraged’ by Trump’s Russia outreach Want to 'drain the swamp'? Implement regular order MORE has acknowledged that although U.S. troops do not have a combat mission, they are still at risk.
"Anybody in a war zone, who's ever been in a war zone, and some of you have, know that if you're in a war zone, you're in combat," Hagel told lawmakers at a House Armed Services Committee hearing on Sept. 18.
Carafano said the president has called for having "no boots on the ground" as way of saying that he does not intend to start another major war. Ruling out the use of ground forces, he said, creates more risk for troops, since it allows ISIS fighters to plot against them.
"What this is going to do is to have lawyers and commanders thinking 'We have to go back to the White House to see if this qualifies as a combat mission,'" he said.
"Being very cautious and risk adverse makes you more at risk for being killed," he said.
Dempsey said on Friday that the advisers would manage the risks, but added, "We can't ever drive risk to zero, but I've … assured the moms and dads out there of these young men and women that we mitigate it and reduce it to … to the greatest extent possible."