Former Defense Secretary Robert Gates says it would 'concern' him if Trump ran for president again

• "Face the Nation" moderator Margaret Brennan asked Robert Gates if a Trump presidential bid would be a national security threat.
• During the CBS interview, the ex-defense secretary expressed "concern" about another Trump candidacy.
• "That's where I am," he said regarding his feelings about the ex-president.

Former Defense Secretary Robert Gates during an interview that aired on Sunday said a 2024 White House candidacy by former President Donald Trump would "concern" him.

When asked by CBS "Face the Nation" moderator Margaret Brennan if Trump's potential return to the Oval Office would pose a national security threat, Gates expressed some hesitancy.

"It would concern me," said Gates, who served as the director of Central Intelligence from 1991 to 1993 and was the nation's defense secretary from 2006 to 2011 under former Presidents George W. Bush and Barack Obama.

When Brennan said his response was "a very diplomatic phrase," Gates conceded that was his current sentiment.

"That's where I am," he responded.

His comments came as Brennan mentioned Mark Esper's bombshell book about his time in the Trump administration, in which the ex-defense secretary said that the former president wanted to shoot demonstrators protesting the death of George Floyd and alleged that allies of the former commander-in-chief called him disloyal for refuting Trump's claims about the slain Iranian Maj. Gen. Qassem Soleimani.

Gates told Brennan he wasn't aware of the alleged threats to shoot protestors or launch missiles into Mexico, as Esper wrote in "A Sacred Oath," but said he was informed of "a few" other ideas that were floated by Trump.

"People would call me from the Pentagon and tell me that ... we're wrestling with how to respond to this," he said. "So I had some flavor of it, but none of the kind of detail that Mark Esper has in his book."

Gates in past interviews has not had the warmest words for the former Republican commander-in-chief.

In a January 2020 interview with PBS NewsHour, Gates blasted Trump as divisive.

"It's quite clear that being a unifying president is pretty low on the priority of our current incumbent," he said at the time. "I think he is a divider, and I think he does so quite consciously."

The longtime Washington official also had critical words for the Republican Party, declaring in a May 2021 "Face the Nation" interview that the presidents whom he served under would not recognize the current iteration of what the party has become.

"I worked for eight presidents. Five of them were Republicans. I don't think any of them would recognize the Republican Party today. The values and the principles that the Republican Party stood for under those five presidents are hard to find these days," he said at the time.

Gates during his Sunday interview also lamented the state of longstanding institutions after Brennan pointed to the leak of the Supreme Court draft opinion overturning Roe v. Wade, the 1973 decision that afforded women the constitutional right to an abortion.

"I went to Washington 56 years ago and I cannot ever recall a leak like that coming out of the Supreme Court," he said. "The thing about leaks is they destroy institutional trust. [Former Secretary of State] George Shultz always used to say trust is the coin of the realm. And on so many really significant decisions in the past, there have been no such leaks."

He added: "I worry it's just a reflection of the continued deterioration of the political climate in this country that now it's even affecting the Supreme Court."