Libertarian presidential candidate Gary Johnson committed a major gaffe on MSNBC this morning when discussing the Syrian civil war.

Asked on “Morning Joe” what he would do about Aleppo -- the major Syrian city that has been a stronghold for opposition forces and under siege by Bashar al-Assad’s government -- Johnson responded: “And what is Aleppo?”

Since then, #WhatIsAleppo has been trending on social media and some have speculated that the incident would doom his campaign.

On "The Five" today, Greg Gutfeld said it was "painful" to watch, but he was impressed that Johnson "owned it."

"He says he doesn't know what Aleppo is. There are people who do know and don't care," Gutfeld said. "I think that there are worse things that are said."

Meghan McCain said she was not surprised by Johnson's lack of knowledge about foreign policy and national security because isolationism is a hallmark of libertarian thought.

"I always think libertarianism is something that works very well in a political science classroom," McCain said. "But in reality, when we're facing Islamic extremism and terrorist attacks, just saying, 'I'm going to be an isolationist, I'm a non-interventionist, so we're just never going to do anything ever,' why are you surprised he doesn't know what Aleppo is?"

"He has no foreign policy plan, he doesn't care. He's an isolationist," she added, predicting Johnson's campaign will "tank" after this embarrassing gaffe.

Watch more above.

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