B.M. What you’ve just described — is it the root of your fiction? Your ability to think yourself into someone else?

J.L.C. Absolutely. I mean childhood, at my age, is no excuse for anything. But it is a fact that my childhood was aberrant and peculiar and nomadic and absolutely unpredictable. So if I was in boarding school, I didn’t know where I would be spending the holidays. If my father said he was going to come and take me out, it was as likely as not that he wouldn’t show up. I would say to the other boys, I had a wonderful day out, when I had really been sitting in a field somewhere.

Image The young David Cornwell at home. Credit... Ralph Crane/The LIFE Picture Collection/Getty Images

The mixture of solitude and uncertainty fertilized the situation enormously. To which you must add the amazing cast of crooked characters who passed through my father’s life. Inevitably I was making up stories to myself, retreating into myself. And then there was the genetic inheritance I got from my father. This was a man who, while still being pursued by the police, or bankrupt, or Christ knows what, who had done prison time, then boldly stands as a parliamentary candidate. He had a huge capacity for invention. He had absolutely no relationship to the truth. He would come talk to me in the morning and I would challenge him, and in the evening he would say, “That’s not what I said to you.”

S.L. Do you see parallels with President Trump’s view of the truth?

J.L.C. Exactly that. He is the most recent model. Before that it was Robert Maxwell. The parallels are extraordinary. My sister, too, we absolutely recognize the same syndrome. There is not a grain of truth there.

S.L. Do you think the Russians really have something on Trump?

B.M. I can tell you what the veterans of the S.I.S. [the British Secret Intelligence Service, or MI6] think, which is yes, kompromat was done on him. Of course, kompromat is done on everyone. So they end up, the theory goes, with this compromising bit of material and then they begin to release parts of it. They set up an ex-MI6 guy, Chris Steele, who is a patsy, effectively, and they feed him some stuff that’s true, and some stuff that isn’t true, and some stuff that is demonstrably wrong. Which means that Trump can then stand up and deny it, while knowing that the essence of it is true. And then he has a stone in his shoe for the rest of his administration.

It’s important to remember that Putin is a K.G.B.-trained officer, and he thinks in the traditional K.G.B. way.