“Many of them have — have said publicly how worried they are about the possibility of Mr. Trump becoming president,” Gates said in an exclusive interview on “This Week” Sunday. “His unpredictability, his lack of understanding of the complexity of international affairs, his threats, his claims that he’s going to make other countries do things, when, in fact, the president of the United States does not have the power to make them do things.”

“So I think — I think a lot of leaders around the world, both among our friends and potential adversaries, are quite concerned,” Gates added…

“One of the things that worries me, Martha, is that he doesn’t appear to listen to people,” Gates told ABC’s Martha Raddatz. “He believes that he has all the answers, that he is the smartest man in the room.”

“And I’ve worked for some very different presidents – Jimmy Carter, Ronald Reagan, George W. Bush, Barack Obama,” Gates said. “One of the things they all had in common was a willingness to listen to people who had experience, and then make their own independent judgments.”