(ABC News)

Romney campaign senior adviser Eric Fehrnstrom defended Mitt Romney's call to arm opposition forces in Syria, saying it would create "a level playing field" this morning on "This Week."

"They are brave, and they're not going away," Fehrnstrom said of those opposing the rule of Syrian president Bashar al-Assad. "What they need is the capacity to wage a fair fight. So what Governor Romney would do is encourage the United States to work with our partners to identify, organize, and arm the opposition."

"They're going up against vastly superior forces in Assad's army and have suffered 10,000 losses, just slaughtered by the government," Fehrnstrom added.

ABC News' George Will challenged the idea, citing the U.S. effort to arm the opposition to Russia in Afghanistan in the 1980's.

"We armed the Taliban in Afghanistan, and that didn't turn out so well," Will said.

Fehrnstrom agreed that care had to be taken when selecting who to partner with in the opposition, but criticized President Obama for not acting to support moderates in Syria.

"For the last year-and-a-half, this president has not engaged in organizing moderate forces within that opposition," Fehrnstrom said. "So to the extent that there's a vacuum that's being filled by bad actors, that is the president's fault."

When Will asked "How do you stop once you engage?" Fehrnstrom said that Romney is not calling for direct intervention, but arming the opposition "so that there's a level playing field."  Will replied, "That's an intervention."

Obama deputy campaign manager Stephanie Cutter said the president "is commit[ed] to toppling the regime in Syria, but we have to do it in a responsible way that protects our interests."

"If you arm the opposition, then you are responsible for wherever those arms end up," Cutter said. "And I don't think we know that yet."