John le Carré, the author whose nuanced thrillers deftly explored the multiple personal and political complexities of the cold war, has died aged 89. The writer of classics such as The Spy Who Came in from the Cold and Tinker, Tailor, Soldier, Spy died from pneumonia in Cornwall on Saturday, according to a statement released by his literary agent.

In a writing career spanning six decades, le Carré — real name, David Cornwell — effectively defined the cold war thriller, elevating the spy novel to a higher literary form well beyond the flimsy, hard-boiled, action-packed capers common to the genre.

While his novels dealt with much of the “tradecraft” of espionage, sometimes to the annoyance over the decades of working spooks, le Carré looked more closely at the countless, often insoluble, individual and ethical conundrums faced by those in the frontline of a geopolitical conflict where the boundaries between right and wrong were blurred.

Following the fall of the Berlin Wall, le Carré turned his focus to the new shadowlands of the post-cold war world, such as the war on terror and arms and drugs dealing. Jonny Geller, his literary agent, said that with his “complex plots and beautiful prose” le Carré “beamed a harsh light at the injustices of our world”.

From the 1963 The Spy Who Came In From the Cold that launched le Carré’s career to his perhaps most memorable character, George Smiley, the owlish, crumpled spymaster of Tinker, Tailor, Soldier, Spy, which was later adapted into a celebrated television series and film, the author was able to draw on his own experience of working for the British intelligence services.

His family background — seemingly the polished product of an elite British education and the Foreign Office, he was also the son of a conman who spent time in prison and even sought to cheat his own family — was another rich source for his work, most notably in the 1986 book A Perfect Spy, which Philip Roth called the best English novel since the second world war.

Earlier this year, at an event in London on the eve of lockdown hosted by the German ambassador, le Carré spoke about the attraction of spying as a subject, noting that it encapsulated many of the frailties of human nature, most notably an unwillingness to be “real” to oneself.

The British establishment, he added, was particularly susceptible to this in collective form as demonstrated by its reluctance to look at its own and entertain that there may be traitors at the heart of the system.

Ultimately, he said, the particularly British fascination for espionage came down to two powerful strands in the national character: “Latent imperialism and hypocrisy”. The two proved fertile territory for le Carré — and richly rewarding for his many fans around the world.