On Friday, former FBI agent Peter Strzok joined Boston Public Radio, where he talked about the threats to U.S. national security and global democracy posed by the Trump administration, in a conversation spurred by his new book, "Compromised: Counterintelligence and the Threat of Donald J. Trump.”

The conversation began with Strzok reflecting on the president’s false claim, made while he was still president-elect, that he had “no dealings with Russia.”

"There’s nothing wrong with pursuing business opportunities anywhere,” Strzok said. "The issue comes up, particularly with regard to president Trump … when he’s lying about it. Because the minute he says that statement, the minute he makes those claims — it’s false. He knows it’s false, and more importantly, Vladimir Putin and government of Russia knows that it’s false as well.”

The former FBI agent, who played a central role in the investigation into links between the Trump administration and Russia before being publicly fired over anti-Trump texts, said the president's lies not only degrade Americans' sense of truth, but give Russia added leverage over his actions. The result, he concluded, is a United States that's less secure, and a world that's less democratic.

"I think what you see is a movement towards — and what I worry about greatly with another four years of Trump — is that there is kind of a dissolution of this broad gathering of like-minded peoples, of what we consider the core of our democracy," he said, in reference to global alliances like the European Union and NATO. "And that’s dangerous, and it’s going to be harmful, particularly with emerging democracies and with people fighting to bring democracy to those nations."