Here is John le Carré (David Cornwell) discussing the filming of Tinker, Tailor, Soldier, Spy (1979), and praising to the skies the genius of Alec Guiness. It's a great interview, and Cornwell is in full raconteur mode, as well as displaying characteristic insight on the actor's art, what he calls "the controlled schizophrenia of the actor."
He also does a fine impression of Guiness, by the bye.
Here's le Carré on the subject of his breakout book:
The Spy Who Came in from the Cold was the work of a wayward imagination brought to the end of its tether by political disgust and personal confusion. Fifty years on, I don't associate the book with anything that ever happened to me, save for one wordless encounter at London airport when a worn-out, middle-aged military kind of man in a stained raincoat slammed a handful of mixed foreign change on to the bar and in gritty Irish accents ordered himself as much Scotch as it would buy. In that moment, Alec Leamas was born. Or so my memory, not always a reliable informant, tells me.A fascinating, and perceptive man.
Today I think of the novel as a not-very-well-disguised internal explosion after which my life would never be the same. It was not the first such explosion, or the last. And yes, yes, by the time I wrote it, I had been caught up in secret work off and on for a decade; a decade the more formative because I had the inherited guilt of being too young to fight in the second world war and – more importantly – of being the son of a war-profiteer, another secret I felt I had to keep to myself until he died.
But I was never a mastermind, or a mini-mind, and long before I even entered the secret world, I had an instinct towards fiction that made me a dubious fact-gatherer. I was never at personal risk in my secret work; I was frequently bored stiff by it. Had things been otherwise, my employers would not have allowed me to publish my novel, even if later they kicked themselves for doing so: but that was because they decided it was being taken too seriously by too many people; and because any suggestion that the British Secret Service would betray its own was deemed derogatory to its ethical principles, bad for recruitment, and accordingly Bad for Britain, a charge to which there is no effective answer.