U.S. President Donald Trump called into a Fox News talk show, where he was asked to respond to voters unhappy with his decision to start a war against Iran.

“I have to do something to make America great and keep it great,” Trump said, claiming that Iran’s possession of nuclear weapons would undermine those goals.

To emphasize his point, he recalled his uncle, who taught at the Massachusetts Institute of Technology for 41 years and told him “terrible” stories about the potential dangers of nuclear energy.

Trump was then asked whether Iranians might take to the streets — something he had urged them to do in his February 28 speech announcing the start of the war.

The U.S. president told Fox News that Iranians are “afraid” to protest.

“One side has the weapons, and they’re very dangerous weapons… and all they do is shoot at you. People are brave, but they stop being brave when they see people being shot left and right. It started with women about a year ago. We had 250,000 women. They had women being shot by snipers right between the eyes,” Trump said.