Facing a fierce militant enemy that was well-armed and entrenched, elite U.S. Special Operations troops deployed to a wild country in order to coordinate U.S. air power, analyze intelligence and provide military advice to a native force that needed help on the ground. The Americans focused heavily on assessing what the locals could do, but also surveilled enemy positions and called in airstrikes.

That might sound like a description of U.S. military operations in Iraq in recent months. But it’s also a brief history of what American commandos did in Afghanistan in the weeks following the Sept. 11, 2001, attacks in New York and Washington.

With the Taliban, which ran the Afghan government at the time, unwilling to give up al-Qaeda leader Osama bin Laden or his associates, the United States aligned itself with the rebel Northern Alliance. With U.S. assistance, alliance fighters began taking control of the country in October 2001, and had a hand in setting up a new government under President Hamid Karzai. Conventional ground troops — a common harbinger of an official ground war — did not arrive in significant numbers until late November of that year, but the Americans in Afghanistan before then had engaged in fierce combat numerous times.

The comparison between Iraq in 2014 and Afghanistan in 2001 isn’t perfect. For all of its muscle, the Islamic State militant group in Iraq and Syria hasn’t toppled the government in either country, the way the Taliban took over Kabul in the 1990s.

The comparison is relevant, however, when discussing a hotly contested issue in Washington this week: whether the United States will put “boots on the ground” in combat in Iraq or Syria, and what that even means. The question has been discussed regularly by administration officials, military officers, lawmakers and pundits alike,  with varying interpretations.

President Obama told a crowd of U.S. service members at MacDill Air Force Base near Tampa, Fla., on Wednesday that he “will not commit you to fighting another ground war in Iraq,” after Army Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said during a congressional hearing Tuesday that the U.S. could be become involved in ground combat in Iraq against Islamic State militants if the situation warranted it. He cited joint terminal attack controllers, who coordinate air support from the ground, as an example of a kind of U.S. troop who could be embedded with Iraqi units.

On Tuesday afternoon, President Obama told troops at MacDill Air Force Base in Tampa, Fla., that "100 percent of Americans need to support" them and their families. He told them he would not commit them to "a ground war" in Iraq. (WhiteHouse.gov)

Dempsey’s spokesman, Air Force Col. Ed Thomas, clarified later Tuesday that the chairman did not believe there was a requirement for American military advisers to accompany Iraqi troops into combat. White House spokesman Josh Earnest, meanwhile, said Dempsey was “referring to a hypothetical scenario in which he might make a tactical recommendation to the president,” an effort to push back on the discussion.

It’s still unclear what actual role Americans will fill in Iraq. American military advisers — especially Special Operations troops — have engaged in combat missions for years in other countries. Most commonly, they have occurred in Afghanistan, where Special Operations troops continue to not only conduct counter-terrorism raids, but train and advise Afghan commandos.

Advisers have been in combat in other countries in the recent past as well. Consider the Oct. 18, 2011, rescue mission that members of Marine Corps Forces Special Operations Command launched in the Philippines, after a Philippine special operations unit was ambushed and five of them were beheaded on the island of Basilan. The U.S. Marines involved in the response were deployed for a train and assist mission, but found themselves in a bloody battle with numerous casualties.

Current operations in Afghanistan also are worth considering. Obama has said repeatedly that the U.S. will end its combat mission in Afghanistan by the end of 2014, but the Pentagon is still expected to leave behind a residual force next year that will include some 2,000 Special Operations troops. They’ll continue to conduct raids, U.S. generals say, even though the formal combat role has ended.