An Obama challenge: Syrian rebels

One of the questions surrounding President Obama's plan to battle the Islamic State: The ability of rebels in Syria.

At one time, the Obama administration avoided support for rebel forces in Syria, questioning their ability to fight and wondering whether they are really moderates.

Now the Syrian rebels — who are opposed to Bashar Assad's government as well as the Islamic State — are keys to the administration's plan to roll back Islamic State gains in Syria and Iraq, while not using U.S. ground troops.

"We have had a relationship with these fighters now for a couple of years," White House chief of staff Denis McDonough said Sunday on CNN's State of the Union. "They're getting better and more capable."

The administration has asked Congress to approve funding for assistance to the Syrian fighters.

Obama has pledged not to send American combat troops back to Iraq or into Syria. So his plan relies on local fighters — the Iraqi military and the Syrian rebels — to battle Islamic State fighters on the the ground, while the United States expands airstrikes in Iraq and possibly Syria.

"We will take the fight to our enemies without putting our ground troops into the effort," McDonough said on NBC's Meet The Press. "We need ground troops, that's why we want this program to train the (Syrian) opposition that's currently pending in Congress."

Skeptics wonder if the Syrian rebels — and Iraq's military — are up to the task, and whether U.S. ground forces will eventually be necessary.

The plan already calls for some 1,600 U.S. troops in Iraq, in advisory and assistance roles.

Former secretary of State James Baker, appearing on NBC's Meet The Press, said the biggest question about Obama's plan concerns "our, quote, 'partners on the ground' ... And I don't know where they come from."

While the U.S. doesn't need another ground war in the Middle East, Baker said that "we cannot do this without having some forces on the ground that can help our air campaign."

The former aide to Republican President George H.W. Bush predicted that "it's going to be U.S. special ops forces and people like that on the ground."