Sarah Sands: I'm sorry, Yasmin, but you've backed the wrong boor

The particular betrayal by Yasmin Alibhai-Brown in siding with Terry Eagleton against Martin Amis appears to lie in a drink she shared with Amis at Cheltenham Literature Festival last year. "You enjoyed a Ribena, as I recall, while I addressed myself to a powerful scotch," wrote Amis in an open letter to The Independent on Friday. Alas, the Ribena did not prevent Alibhai-Brown from denouncing Amis's views on Islam which she said placed Amis "with the beasts".

First, we should acknowledge that Cheltenham does not guarantee comradely behaviour. It was at this festival, after all, that Kingsley Amis left his wife Hilly for the more Conservative charms of Elizabeth Jane Howard. His nomadic eye for women was the least of his faults, according to Eagleton, who described him as a "racist, anti-Semitic boor, a drink-sodden, self-hating reviler of women, gays and liberals".

This was merely the warm-up to his accusing Martin Amis of aping his father in his hatred of liberalism, expressed through his anti-libertarian antipathy to Islamism. Wouldn't Kingsley Amis have adored all this? His greatest pleasure was tormenting lefties. He presided happily over "fascist lunches" at Bertorelli's, although fellow guests included Bernard Levin and Alan Watkins. One guest recalled that the lunches were mostly gossip; who had run off with whom. Occasionally Amis would remember the purpose and raise a toast to Richard Nixon or Pinochet.

The only time Kingsley Amis lost his reactionary fighting spirit in his later years was in Nashville, where the racism depressed him. "One can forgive a lefty here in that Conservative opinion is so shitty," he wrote. The lefties he most despised were the old ones who thought they could "arse lick" students with "the abortion-divorce-homosexuality-censorship-racialism-marijuana package".

Eagleton, a great dinosaur of Marxism and a convert from Catholicism to boot, is a near perfect Amis creation. Martin Amis has written reflectively of feeling closer to his late father as grows older but he has a fundamental seriousness which Kingsley was determined to avoid. The father used to tease his unhappy son over his apocalyptic views of the nuclear bomb.

Now there is a new "Age of Horrorism", according to Martin Amis, who compares Islamism to Stalinism and Nazism. Although he writes to Alibhai-Brown of "building all the bridges we can" with moderate Muslims, his imagination rests still with the inferno of the twin towers. This has been his literary and moral inspiration. (This may or may not be a good thing. When I visited his mother Hilly Kilmarnock in Spain last summer she said that her son's writing had gone off a bit since London Fields and she was finding William Boyd an easier read.)

There are two reasons why we must back Martin Amis in this fight. The first is that Eagleton is a spiteful old bore who wanted attention rather than serious argument. The other writer to offend him is David Hare who has been wondrously thoughtful and insightful about the War on Terror. The second is that Amis, for all his hyperbole about Islam, has uncovered something decadent about left-wing intellectuals such as Eagleton. Their creed is My Country is Always Wrong and they believe other philosophies must always be preferable, even murderous ones.

I cannot understand how Western feminists can turn a blind eye to Islamic fundamentalism. Kingsley Amis said that the trouble with lefties is that they cannot acknowledge evil. His son has learnt this lesson.