Brexit is the great distraction in British politics; it even complicates the reading of spy novels. And yet John le Carré’s “The Looking Glass War,” published in 1965, seems particularly revealing of the peculiar dynamics behind the United Kingdom’s self-defeating attempts to leave the European Union. The novel centers on “the Department,” an agency that is vaguely focussed on military intelligence and intently preoccupied with its own bureaucratic marginalization—it is being pushed out of the game by “the Circus,” an agency that employs George Smiley, one of le Carré’s great spying creations. The action is set in motion by what is probably fake news planted by the Russians. In response, the Department constructs an utter shambles of an operation, built on little more than memories of imperial glory, Oxford connections, a resolute indifference to the customs of other countries, and a faith in the infallible effect of muddling. The Department is, in effect, stacked with proto-Brexiteers.

The Department’s basic plan (there are spoilers here) is to infiltrate an agent into East Germany to confirm a report, from a “defector” whose story is full of holes, about missiles being deployed there. The agency decides that he should sneak across the border on foot, with a forged I.D. card. Beyond that, the planners—Leclerc, an old R.A.F. hand; Adrian Haldane, his contemporary; and the younger and still idealistic John Avery—haven’t really thought things out. They recruit Fred Leiser, a German-speaking Pole who worked in military intelligence during the war but has long since settled down as a garage owner—a life they casually ruin—for little reason other than that his name appears in their outdated card file. When Leclerc gets word that Leiser has, quite reasonably, turned them down, he lashes out at Haldane, “Good God, what about the Department! Didn’t that mean anything to him? You don’t believe in it any more, you don’t care! You’re sneering at me!”

At that, one hears the injured voices of Brexiteers who try to dismiss any skepticism about their mismanaged project as a mere lack of national faith. Boris Johnson, the former Foreign Secretary, who is on track to become Prime Minister in the next couple of weeks, has been proclaiming that every Brexit obstacle will vanish if people just “Believe in Britain.” Johnson would fit in well in “The Looking Glass War.” When, in the novel, East German police first see signs that there might be a spy in their territory, one says that “it must be a child,” so reckless are his moves. Johnson’s imprudence has too often been explained or excused as a kind of perpetual boyishness. Supposedly serious British politicians continue to do so.

Indeed, after Leclerc’s outburst, one can hear in the responses of his colleagues different aspects of the contemporary Conservative Party’s surrender to Johnson and his cohort. “Who of us does believe?” Haldane says, but adds, “We do the job.” Avery interjects, “I believe,” and persuades Leiser to believe, too, even as he comes to know, better than the others, “the fatal disproportion between the dream and reality.” He listens to Leclerc’s absurd plan “with the piety of an agnostic, feeling perhaps that this was how, in some clean and magic place, it really ought to be.”

Belief does not erase complicity. At one point, Haldane hustles away a blowhard colleague, Bruce Woodford, to prevent him from meeting Leiser, citing “security,” although any pretense to secrecy has long since been blown. (Even the body of a courier killed in a traffic accident has been mishandled, in a darkly comic way that exposes the operation to the London police.) Le Carré writes, “Avery knew then that Haldane was determined to preserve Leiser in the delusion that the Department housed no fools.” One thinks of the attempts of the establishment Brexiteers, back during the referendum campaign, to distance themselves from Nigel Farage’s embarrassingly crude populism while also making use of it. Now they are openly, desperately envious of how many votes Farage’s new Brexit Party gets in the polls.

Le Carré, in a 1991 introduction to “The Looking Glass War,” wrote that he had intended the Department as a counter to the image of the very clever intelligence agency, with all sorts of tricks, that he had put forward in “The Spy Who Came in from the Cold”—it would be “a deliberate reversal, if not an actual parody,” of the earlier book. “Such an outfit, if I got it right, would speak not only for the British Intelligence community of the ’sixties . . . it would presume to speak also for Little England itself.” He wanted, he said, to capture the condition of “a political somnambulant” that fights, uncertain of the enemy or aim, “because not to fight is to wake up.” More recently, le Carré has spoken out against Brexit, including in an open letter that he signed, along with Neil Gaiman, Philip Pullman, and other writers, in May and, indirectly, in his novel “A Legacy of Spies,” which was published in 2017, the year after the Brexit referendum. “I’m a European,” he has an aging Smiley say. “If I had a mission—if I was ever aware of one beyond our business with the enemy, it was to Europe. . . . If I had an unattainable ideal, it was of leading Europe out of her darkness towards a new age of reason. I have it still.”

One prescient aspect of “The Looking Glass War” is that it illustrates not only the impoverished ideal behind Brexit but the tendencies that have led to it being a disaster in practical terms. At one point, Leclerc tentatively tries to get Leiser the latest radio equipment from Smiley at the Circus:

“Is that a method in which our people could profitably be trained . . . in a month, say?” “And use under operational conditions?” Smiley asked in astonishment. “Straightaway, after a month’s training?”

As Leclerc explains that some people are “technically minded,” Smiley watches him “incredulously,” and continues, “Forgive me. Would he, would they . . . have other things to learn in that month as well?” Yes—just as the United Kingdom would have any number of things to do before the Brexit deadline, now October 31st. Brexiteers have filled the time up until now with hand-waving about how “technology” can solve complex issues such as the future of the border with the Republic of Ireland. Basic matters related to trade, health care, and residents’ rights are unresolved. “We play the war rules” is the Department’s reflexive response to practical obstacles; “We’ll exit on W.T.O. terms” has become a standard dodge of Johnson and other No Deal Brexiteers—ignoring that such “terms” offer nothing more than the defaults that apply to least-favored nations in the World Trade Organization.

Smiley turns down Leclerc’s equipment request, in part because the Department has presented the whole thing as a “training exercise”—the seriousness of the enterprise has been fatally underplayed in some quarters while the drama has been overplayed in others. Leiser is instead sent into the field lugging a fifty-pound radio set left over from the Second World War. His handlers have pretended to persuade themselves that this is for the best, because he is familiar with it, just as they are most comfortable when thinking about the past.

In February, Donald Tusk, the president of the European Council, said, “I have been wondering what the special place in hell looks like for those who promoted Brexit without even a sketch of a plan how to carry it out safely.” One possibility is that it resembles the desolate farmhouse in which Avery, realizing the damage they all have done (the operation is a calamity, and Leiser has been abandoned in East Germany), buries his head in his hands and sobs “like a child,” while Leclerc natters on about inviting Smiley to dine with him at his club.