In an interview broadcast Sunday morning on CBS News’ Face the Nation, President Donald Trump said America needs to keep troops at their posts in the “unbelievable and expensive military base built in Iraq” in order to “watch Iran.”

Trump made this comment after interviewer Margaret Brennan questioned him at great length about his plans to withdraw troops from Syria and Afghanistan. Brennan highlighted Trump’s public disagreement with members of the intelligence community about the need to keep U.S. forces in Syria to fight the remnants of the Islamic State.

“We’ve done an incredible job with Syria,” Trump stated. “When I took over Syria it was infested with ISIS. It was all over the place. And now you have very little ISIS and you have the caliphate almost knocked out.“

Trump said the Islamic State has been stripped of 99 percent of its Syrian territory so far, and the U.S. military will soon be able to announce 100 percent has been reclaimed. He stressed that recovering territory from ISIS is not the same thing as completely eliminating the terrorist organization, which will always have “pockets” of activity from which it can launch occasional terror attacks.

“When I took over it was a disaster,” he repeated. “I think we’ve done a great job with that.”

Trump contrasted this remarkable success with America’s 19 years in Afghanistan, at a cost of 50 billion dollars a year, and noted the U.S. involvement in Syria lasted for “years” longer than originally promised during the Obama administration.

Trump emphasized the base in Iraq gives the U.S. a vital capability to quickly project both air and ground power across the region if needed, repeatedly expressing his surprise at visiting the American airbase in Iraq and observing firsthand how large and sophisticated it is.

“We’ll come back if we have to. We have very fast airplanes, we have very good cargo planes. We can come back very quickly, and I’m not leaving. We have a base in Iraq and the base is a fantastic edifice. I mean I was there recently, and I couldn’t believe the money that was spent on these massive runways,” he said.

When Brennan mentioned Trump’s criticism of President Obama for withdrawing from Iraq and opening the door to the Islamic State invasion, Trump responded his own drawdowns in Syria and Afghanistan are different because “I’m not telegraphing anything,” and because Obama’s withdrawal jeopardized a strategic asset the United States paid dearly to develop.

Trump made a point of disagreeing with President George W. Bush’s decision to invade Iraq, calling it “one of the greatest mistakes going into the Middle East that our country has ever made,” but said the American foothold in Iraq should now be leveraged to make long-term deployments in other Middle Eastern hot spots unnecessary.

“Well, we spent a fortune on building this incredible base. We might as well keep it,” was Trump’s pithy summary of his view on the matter.

The president then astounded Brennan by saying one of the reasons he wishes to maintain the U.S. base in Iraq is “because I want to be looking a little bit at Iran, because Iran is a real problem.”

“Whoa, that’s news. You’re keeping troops in Iraq because you want to be able to strike in Iran?” Brennan exclaimed.

“No, because I want to be able to watch Iran. All I want to do is be able to watch,” Trump replied.

“We have an unbelievable and expensive military base built in Iraq. It’s perfectly situated for looking at all over different parts of the troubled Middle East rather than pulling up. And this is what a lot of people don’t understand. We’re going to keep watching and we’re going to keep seeing and if there’s trouble, if somebody is looking to do nuclear weapons or other things, we’re going to know it before they do,” he elaborated.

Trump implied better practical intelligence on Iran’s activity is vitally needed because too many of his critics seem to believe Iran is “a wonderful kindergarten.”

“It is a vicious country that kills many people when you talk about torture and other things,” he said.

Trump expressed hope that Iran might change for the better now that the United States has withdrawn from the Iran nuclear deal and restored sanctions on the brutal regime in Tehran.

“It was a horrible deal done by President Obama and John Kerry that didn’t know what the hell he was doing. When I ended that deal, Margaret, all of a sudden Iran became a different country. They became, very rapidly… right now they’re a country that’s in big financial trouble. Let’s see what happens,” he told Brennan.

“We were in many many locations in the Middle East in huge difficulty. Every single one of them was caused by the number one terrorist nation in the world, which is Iran,” Trump said. “So when my intelligence people tell me how wonderful Iran is, if you don’t mind, I’m going to just go by my own counsel.”