(CNN) Fred Hof, former U.S. special adviser for a transition in Syria, told CNN's Christiane Amanpour on Wednesday that he believes if given a second chance, U.S. President Barack Obama would have taken his national security team's advice in 2012 to set up a robust arm and train program for the moderate Syrian opposition.

At the time, President Obama knocked down the proposal , which was supported by then-Secretary of State Hillary Clinton, then-CIA Director David Petraeus, then-Defense Secretary Leon Panetta, and then-Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey.

Former Official: We took 'Assad must go' as a directive

Former Official: We took 'Assad must go' as a directive 11:11

Former Official: We took 'Assad must go' as a directive

The Pentagon did begin a train and equip program this spring, but shut it down earlier this month; the general in charge of U.S. Central Command said only four or five American-trained fighters were still in Syria.

When asked for comment, the White House pointed to President Obama's recent interview with CBS' "60 Minutes ," in which he said he was "skeptical from the get go about the notion that we were going to effectively create this proxy army inside of Syria."

During Hof's live interview, he said that "trying to hold this thing [the war in Syria] at arm's length becomes the operational equivalent of pouring gasoline on a fire."

But that inaction took him by surprise.

It was in 2011, several months into the Syrian uprising, that President Obama laid down the gauntlet for Bashar al-Assad for the first time.

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"The time has come for President Assad to step aside," President Obama said at the time in a written statement.

"For many of us," Hof said, "when the President made that statement, those words were directive in nature."

"The President of the United States doesn't issue advisory opinions to people. He is the commander in chief. When he said Assad should step down, many of us in government thought, alright now it's our duty to come up with a strategy to make it happen."

"After a period of time elapsed it became clear there was no real interest in the White House for doing that."

While Hof said he understands the President's desire to hold the conflict "at arm's length," he thinks that strategy has backfired.

Tuesday brought news that the United States is now considering ground action as part of its anti-ISIS strategy, which to this point has been limited to airstrikes and assisting Kurdish and Iraqi forces.

"We won't hold back from supporting capable partners in opportunistic attacks against ISIL," U.S. Defense Secretary Ash Carter told the Senate on Tuesday, "or conducting such missions directly, whether by strikes from the air or direct action on the ground."

President Obama "needs to look at some real options," Hof said.

"Even if he does not look at civilian protection in Syria through a humanitarian lens, he should be looking at it through a war-fighting lens, because every barrel bomb, every starvation siege is a gift to ISIS. It's a recruiting gift."

"I think it's inevitable that at least in the realm of special operations the United States will look for opportunities on the ground in both Iraq and in Syria."