Michael Lewis has made his brilliant journalistic career by finding engaging human stories to illuminate the data-driven, risk-avoiding complexities of our world. In The Big Short Lewis brought to life the extraordinary black comedy of those who had made fortunes betting on the global financial crash. Moneyball examined the characters behind the new science of success in sports. His most recent book, The Fifth Risk: Undoing Democracy, applies his insider’s eye to unsung heroes of government administration, in light of the reckless dismantling of the US civil service under Trump. Lewis defines the fifth risk to civilisation – alongside more visible contenders like climate crisis and nuclear conflict – as a loss of faith in the mission of effective governance, “what you never learn that might have saved you”.

The afterword to your new book, written after Trump’s shutdown of government in January 2019, describes the life of Arthur A Allen, whose innovations in air-sea rescue for the US Coastguard saved countless lives in the course of his long career. He was among tens of thousands of civil servants considered expendable by Trump’s regime. Why do you think stories like his have been so rarely heard?

There is less diversity in the news. It has gotten harder and harder to tell a small story that is actually a big story. If you don’t start with a celebrity, it is harder to persuade people to take an interest in it. It is almost the reverse of what has happened in entertainment. Netflix has worked out how to make these very niche dramas and comedies and make them universal. News is much less good at it.

In both our countries we are being sold the line by populists that the civil service, public service in general, is wasteful and bureaucratic; dull. That was clearly not your experience?

I actually purposefully chose the departments I thought would be least interesting: energy and agriculture and commerce. I avoided defence and treasury and state. I wanted to show you could drop people into any part of American government and find hundreds of stories that are of potentially earth-shattering importance. I wanted the reader to have the sense: “My God, even here there are things I need to know and worry about.”

When you have done readings from the book, how have audiences reacted?

I never found anyone who said: “You are exaggerating the importance of these people.” The closest I got to the Trump administration was to talk to Steve Bannon about it. Bannon had this election line: “We are going to tear down and destroy the administrative state.” I asked him what on earth he meant by that. What would it mean to destroy the Department of Agriculture, say? He didn’t really even try to answer. What we are witnessing is a decline in interest in how you fix other people’s problems.

Part of your story examines the consequences of the ideological cull of climate scientists from government. You have lived in close proximity to wildfires in California, there have been unprecedented hurricanes. Do you think there will come a point when people demand leaders who understand the importance of scientific knowledge?

You would think so. It hasn’t happened yet. For people to suddenly start to value what good government does, I think there will have to be something that threatens a lot of people at once. The problem with a wildfire in California, or a hurricane in Florida, is that for most people it is happening to someone else. I think a pandemic might do it, something that could affect millions of people indiscriminately and from which you could not insulate yourself even if you were rich. I think that might do it.

That is quite an apocalyptic thought. You have always seemed by nature an optimist, are you feeling more nihilistic about what you call the drift of things?

I’m a little more wary than I have been. What we are seeing is an attack on the idea of progress and the idea of science. In the Trump administration there seems to be a total lack of respect for expertise. It sounds like you have something of the same with Boris Johnson. For this kind of attack to work you need to have characters who don’t care at all about consequences.

Where do you think that disregard comes from?

I think there is a deeply corrupt streak in a lot of it. If you want your polluting to succeed then you remove from power anyone who cares about pollution. It is a celebration of ignorance for the purpose of profit. Part of it is status-based, too: people don’t like feeling stupid. They don’t want to be told what to do by people with fancy educations. You can see that even within Trump’s family. Donald Jnr and Eric have probably been made to feel stupid by their peers. Now they can say: “If you are so smart, why aren’t you rich and powerful like me?”

You still seem to see this as a historical blip, though. Could you actually be writing the Decline and Fall of the American Empire?

It could be that. But my gut says don’t bet against the country. It has this incredible capacity for self-reinvention. If it was Britain and this was happening I would say yes, it might be a one-way ticket to decline. But in the States I think something will come along that will finally induce the requisite state of terror – and it will regenerate the place.

The Fifth Risk is published in paperback by Penguin £9.99. To order a copy for £8.79, go to guardianbookshop.com or call 020-3176 3837