Republican presidential hopeful Ted Cruz has defended his plan to "carpet bomb" civilian areas occupied by ISIS in the face of critics who have said the idea was unworkable and illegal.

During a December GOP primary debate, CNN's Wolf Blitzer pointed out that Cruz had said that the U.S. should "carpet-bomb ISIS into oblivion" to find out whether "sand can glow in the dark."

Cruz replied: "What it means is using overwhelming air power to utterly and completely destroy ISIS."

On Sunday, Fox News host Chris Wallace asked Cruz to respond to military experts who have insisted that "carpet bombing ISIS would never work."

In fact, former commandant of the U.S. Army War College, Robert Scales, argued that carpet bombing was "just one of those phrases that people with no military experience throw around."

"I will apologize to no one with how vigorous I will be winning the war on terror," Cruz replied. "We will start by having a president who will acknowledge our enemy, say it by its name, which President Obama and Hillary Clinton refuse to do."

"And you want to know what carpet bombing means?" he continued. "Yesterday was the 20th anniversary of Desert Storm. In 1991, we had roughly 8,000 planes. Today, we have 4,000. Our Air Force has dropped in half. In 1991, we had 591 ships in our Navy. Today, we have 272. It's dropped nearly in half. In 1991, we had over a third more soldiers in our Army."

"And we were launching 1,100 air attacks a day. We were carpet bombing them. And after 37 days of 1,100 air attacks a day, our troops went in in a day and a half and mopped up the remnants of the Iraqi Army because that's the effect of carpet bombing."

Wallace, however, noted that the U.S. military leaders insist that carpet bombing was never used in the first Gulf War.

"We did precision striking," Wallace said. "In addition -- if I may -- the Iraqi Army was all massed by itself in the Kuwaiti desert. We're now talking about ISIS soldiers who are not massed, they are embedded in Mosul, they're embedded in Raqqa with civilians."

Cruz shot back that the current U.S. strategy was "photo-op foreign policy."

"We're not taking out the oil fields, we're not taking out... Jihadist University, where they are training jihadists," Cruz said. "Why isn't that building rubble? We're not using overwhelming air power."

"We can defeat them, but we can't defeat them if the president is unwilling to do so. And as president, I will defeat ISIS," the Republican hopeful concluded. "We will utterly destroy them. And it takes a commander-in-chief directing our forces to do that."