more about Hector Meredith...

“Le Carré needs the cold war rather badly," wrote Ian Hamilton in 1980. Thirty years later, speculation has become truism. Despite the existence of conflicts about which he may acquire knowledge and around which he can spin plots, John le Carré has yet to find one to prompt the old ambivalence. At the end of The Spy Who Came in from the Cold, Alec Leamas sets out his position to his one-time girlfriend Liz: "It was a foul operation. But it's paid off, and that's the only rule." That word "only" catches the inevitable moral cost of the spy's pragmatism. Unfortunately, tales of the war on terror or corruption in Africa do not lend themselves to shades of grey - at least not as le Carré tells them. Foul deeds are shown to have abject motives; immorality has replaced amorality as the reigning vice.

But the now-familiar allegation that le Carré's relevance crumbled along with the Berlin Wall fails to account for other aspects of decline. It does not explain, for instance, his taste for a large canvas, with the result that thin tales of conspiracy and greed (The Tailor of Panama, The Constant Gardener) are drawn out to the same length as the necessarily hefty historical and biographical saga A Perfect Spy; it does not explain the preference for polemicising over carefully plotted action, as displayed in Absolute Friends; and it does not explain the looseness and crudity of his 22nd novel, Our Kind of Traitor.

When Perry Makepiece, a 30-year-old Oxford don, is offered a fellowship at his "ancient, rich, achievement-driven college", he sees it as "imprisonment for life". Confronted with the "stifled" Britain of 2009, Perry's hero George Orwell "would have smashed some serious glass", so why is he content with gowns and spires? As for Perry's girlfriend, Gail Perkins: "Should Gail give up the Bar and step blindly into the azure yonder with him, or should she continue to pursue her meteoric career in London?" Perry will be lucky if she does the former: "Nature had provided Gail with long, shapely legs and arms, high, small breasts, a lissom body, English skin, fine gold hair and a smile to light the gloomiest corners of his life."

With those powers of argument and that torch-like smile, Gail has no difficulty persuading Perry to book a holiday to a tennis resort in Antigua, where they encounter the Russian gangster and wannabe whistleblower "Dima", Dmitri Krasnov. This chance meeting catches the attention of "British agents professionally disposed against the working of chance" - in particular, washed-up and jockey-like Luke and the mysterious bluestocking Yvonne.

Le Carré used to resemble Leamas - "Not a wasted word did he speak" - but these days he is closer to Leamas's shady superior Control, who "talked a lot of drivel before getting the knife in". In Our Kind of Traitor, the chat blocks the plot. Instead of restricting himself to describing the circumstances preceding Perry and Gail's interrogation by Luke and Yvonne and its narrative consequences in London, Paris and Switzerland, le Carré is interminably distracted by the inner lives and backstories of characters we may be encouraged to root for, but are unlikely ever to care about.

Even in his tighter-lipped and more targeted books, the author has shown a weakness for "deathly" silences, "terrible" clarity and the "bitter" cold - as well as bitter ends, bitter tears and bitter experience. Now the reliance on cliché and corridors-of-power myth-making is accompanied by clanging wordplay, such as "Gail's sky is darkening, and so also is the basement room". Le Carré helped to promote genre writing into a species of literature; writing of this kind risks reversing the process.

His dialogue displays similar signs of mis­firing instincts. Dima is given to messing up basic sentences but always swears impeccably; his daughter Natasha "don't give a shit about tennis, love books", which is presumably why she describes her prospective mother-in-law as "inhabited by bourgeois instincts, also loquacious". Oddly, le Carré's "espiocrats" are no less rough-hewn, the director of special projects, Hector Meredith, being an especially preposterous and wearying creation. He congratulates Perry on his "fabulous fucking article" about "Edmund bloody Blunden", "Siegfried bloody Sassoon" and "Robert bloody Graves"; he also "happily" describes a meal as "the second-worst lunch in the world, first prize yet to be awarded". In all of the book's streams-of-consciousness, no one dismisses Hector as a throwback or a bore.

But even when le Carré fails to provide so many of the pleasures that are within his reach as a thriller writer and conjectural historian, he retains the power to make us feel like insiders in a previously remote and whispered-about world. Hector explains that secret agents play a different game from diplomats, who lie to protect their country, and politicians, who lie to save themselves: "according to the ground-floor gossips", the Midlands accent of Hector's superior Billy Boy Matlock "had become more noticeable under New Labour, but was receding with the prospect of electoral defeat". These are small-scale victories; we need dozens of them, not the handful we get here. Still, they provide a glimmer of the old evocative swiftness - and a reminder of why, after so much bitter disappointment, there is still a naked hunger, or perhaps a burning desire, for yet another novel by John le bloody Carré.