Taylor said then-Defense Secretary James Mattis cornered him one day after a Situation Room meeting.

“’All of you should prepare as if we were going to war,’ he warned. Mattis was serious. DHS should assume the homeland was in mortal danger.»

The Department of Homeland Security took a step it had never taken before, according to Taylor, who is best known for writing an anonymous opinion piece in The New York Times in 2018 describing a “silent resistance” in the Trump administration “of people who choose to put country first.”

“We convened all of the top DHS leaders to discuss the crisis that is brewing,” he writes in the new book, which will be published July 18. “The experts went over various scenarios of a nuclear attack on the homeland of the US, outlining the best scenarios that nonetheless sounded terribly bleak. I can’t provide the details, but I came away from those meetings genuinely concerned about the security of the country. In my opinion, the department was not prepared for the type of nuclear conflict that Trump could foment.»

Chris Krebs, a senior DHS official at the time, confirmed that in 2017, department officials discussed how they would respond to a nuclear attack on the United States.

“There was certainly a feeling that there was a non-zero chance and therefore we should take appropriate and reasonable steps to assess readiness for such an attack,” Krebs told POLITICO.

On November 28 of that year, North Korea tested a missile that could have reached the continental United States. The test sparked fear throughout the US government, including DHS. Then-Acting DHS Secretary Elaine Duke supervised him from a secure conference room, Taylor added, and spoke with her after the test. She told him that the president had called her after the launch. But it was not to talk about North Korea. Rather, she wanted to talk about the upcoming DHS decision on whether to extend temporary legal protections for Hondurans who have arrived in the United States.

«Although a nuclear-capable missile had just streaked across the skies, the president’s mind was on the border,» Taylor’s book says. «He wanted DHS to ‘deport them all,’ Elaine recounted.» Duke, however, decided to extend those legal protections.

The DHS fight to prepare for a nuclear attack was a first, according to Taylor.

“This is the first time that I know of that DHS thought there was a possibility, however remote, that Trump would actually start a war and we would have to prepare for nuclear fallout at home,” he told POLITICO in an interview.

In his 2018 New York Times op-ed, Taylor called Trump’s leadership style «impulsive, contradictory, petty and ineffective.» In 2019, she anonymously wrote a book exploring the subject. And in 2020, he endorsed Joe Biden’s presidential campaign and came out as the anonymous author.