Former Secretary of State John Kerry, left, speaks alongside former Secretary of Defense William Cohen at the University of Maine on Nov. 5, 2019.

On Dec. 19, 2018, former Secretary of Defense William Cohen was about to do an interview on the BBC when he was handed a note telling him that President Donald Trump had ordered the withdrawal of all U.S. troops from Syria.

He finished the interview and did something he’d never done before. He called then-Secretary of Defense James Mattis, who confirmed the news.

“I said, ‘When?’ And he said, ‘immediately.’ And we hung up,” Cohen said. “I didn’t ask him what he was going to do, but I knew what he was going to do.”

The next day, Mattis went to Trump try one last time to ask him to reconsider, Cohen said. When Trump refused, Mattis submitted his resignation letter.

“I share the same viewpoint as Secretary Mattis, that we are safer when we work with other countries, when we trust them and they trust us,” Cohen said. “Once they lose that sense of trust, we’re in deep trouble.”

Cohen, a Bangor native and former Maine senator and congressional representative, appeared Tuesday at the University of Maine with John Kerry, who served as secretary of state under President Barack Obama, after nearly 30 years in the U.S. Senate representing Massachusetts.

Cohen and Kerry lamented a variety of international relations decisions that Trump has made since taking office in 2017 and the political divide at home that has deepened during his presidency. Their discussion at the Collins Center for the Arts was the 12th installment in a biennial event called the William S. Cohen Lecture Series that’s organized by UMaine’s Cohen Institute for Leadership and Public Service.

Both Kerry, a Democrat, and Cohen, a Republican who served in the Cabinet of Democratic President Bill Clinton, talked about Trump’s tendency to bypass his own intelligence and cabinet in making decisions concerning diplomacy.

“When you bypass the institutions that have been set up and say I know more than everybody, then you’re veering into one-man rule, and that is dangerous for our country,” Cohen said.

Kerry, a Democrat, said that Trump’s presidency has resulted in a deepening partisan divide in Congress.

“We worked together. We didn’t think about each other as Republican or Democrat,” he said.

“We really thought of ourselves as senators acting in the interest of our nation.”

Both Kerry and Cohen have continually called Trump out publicly over the past few years. Cohen called him a dictator in an interview with CNN last week, and Kerry called for the president’s resignation in January.

Both former cabinet members support the impeachment inquiry.

“This is a very serious moment. It’s a constitutional challenge,” Kerry said. “I think there are a series of behavior episodes ranging from the Mueller report to the Ukraine situation that are completely justified to be part an inquiry right now.”

Cohen said he thinks Maine Sen. Susan Collins — one of the few Republicans in Congress who has not taken a stance on the impeachment inquiry — will weigh the facts before making her choice.

“It’s a tough position for anyone there to be in now because of President Trump’s popularity with the Republican base,” Cohen said. “It’s easier for me to say what I think. I don’t have to account for it. She will.”

However, he thinks Collins has a reputation for representing the interests of Mainers in the Senate. Her decision on impeachment will not keep her from getting re-elected in 2020, Cohen said.

“I think the people of Maine will ultimately support her in the election either way,” he said.