Writers have always conducted colourful feuds, and the García Máarquez-Vargas Llosa vendetta was one of the best. Once they were the closest friends. García Márquez was godfather to Vargas Llosa’s son. Then relations cooled, their political paths diverged, and three decades ago, for reasons that have never been fully explained by either side, the friendship came to an end with a fierce fist-fight in a Mexican cinema.

The art of the feud seems to be dying out. Writers once exhibited their sworn enemies with as much pride as any literary award. Politicians delighted in grudge and vengeance, and waded happily though rivers of bad blood. Artists openly slopped paint and vitriol over one another.

Public figures are no more tolerant of one another than they ever were, but in an age of false politeness and fake amity, the old-fashioned blood feud is increasingly rare. Only a few staunch figures still cultivate their enemies with proper care.

This week, Robin Cook offered a timely reminder that it is perfectly possible to settle old scores when you are dead. His gravestone epitaph — “I may not have succeeded in halting the war, but I did secure the right of Parliament to decide on war” — captured the man precisely: needling, defensive and determined to have the last word, carved in stone. In life, Cook was so bristling and unlovely that it was said he could create an ugly scene when left alone in a room. I admired him greatly.

Norman Mailer, the veteran fighter-writer, is another who upholds the long-established tradition that if you can’t beat ’em, thump ’em. Mailer sat on Truman Capote, headbutted and punched Gore Vidal, and stabbed his first wife with a penknife when she called him a “faggot”. He wrote to William Styron, after a disobliging review: “I will invite you to a fight in which I expect to stomp out of you a fat amount of your yellow and treacherous shit.” Now walking on two sticks, aged 83, and partially blind, Mailer is still lashing out with admirable venom, most recently at The New York Times book critic Michiko Kakutani (“a one-woman kamikaze”).

A feud is very different from a disagreement over principle, a rivalry, or mere mutual antipathy. Julie Burchill is adept at manufacturing fights that look like feuds, but are really only the ritual exchange of insults. The term “feud” is too often applied to a disagreement between two people who happen to have a computer and a taste for publicity.

A genuine feud must be personal, prolonged, public, petty and so encrusted with ancient anger that only the participants (and possibly not even they) can remember how it started. The best feuds are nurtured over a lifetime, delivered in the form of steel barbs, sharpened with malice aforethought. Revenge should be served not only cold, but with the most elaborate garnish. Bevis Hillier recently served up such a dish to A.N. Wilson, his rival Betjeman biographer, by planting on him a fake letter from an invented mistress in which the first character of each sentence spelt an offensive message.

Most important feuds are sparked by something entirely unimportant. Vladimir Nabokov and the critic Edmund Wilson fell out after a quarter-century of close friendship over the precise translation of a single Russian phrase in Pushkin’s Eugene Onegin.

The troubled relationship between Tony Blair and Gordon Brown is often described as a feud, but fails the test in several respects. The cause of their conflict is too specific and obvious. There is no direct confrontation. In public they maintain an utterly unconvincing harmony.

The joy of Cook and Mailer was their eagerness not only to give but to take offence openly; to respond to an original slight, whether intended or not, with overwhelming and disproportionate rudeness; to hone resentment over time, and deliver the insulting punchline immediately after the punch. “Words fail Norman Mailer yet again,” said Vidal, after Mailer had floored him with a single blow in a television studio. The remark was far too brilliant to have been spontaneous.

These are the hallmarks of the truly great feud. Never forgive or reconcile. Never back down. Land the first blow and extract the last laugh, even if that means chiselling it onto your headstone. (“I told you I was ill!” wails Spike Milligan’s epitaph.) Above all, take the fight to the enemy. In 1936 Wallace Stevens the poet, drunk, accosted Ernest Hemingway at a party and sneered: “So, you think you’re Ernest Hemingway?” The resulting punch-up left both writers battered, and even more famous.

That is what makes the Blair-Brown feud-by-proxy (and the García Márquez-Vargas Llosa rapprochement) so dreary. I suspect that the two great literary lions of Latin America still dislike one another heartily. We know that Mr Blair and Mr Brown do. But the rules of modern hypocrisy value bogus bonhomie over honest animus. In the literary world, back-scratching sells more books than eye-gouging. Mr Blair and Mr Brown must conduct their quarrel in venomous whispers, behind their hands.

Once, just once, I would love to see Mr Brown square up to his rival, poke him in the chest, and declare: “So, you think you’re Tony Blair?”

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