"ABOUT suffering, " Auden famously wrote in 1938, "they were never wrong, / The Old Masters: how well they understood/ its human position; how it takes place/ While someone is eating or opening a window/Or just walking dully along." Yet the great crucifixion paintings of Caravaggio or Bellini, though they were not what Auden had in mind . . . have God on their side. We may feel the power of suffering in the context of religion but, outside this spiritual setting, I'm not sure how compassionate we really are.

The atrocities of yesterday . . . the Beslan massacre, the Bali bombings, the terrorist attacks of 11 September 2001, the gassings of Halabja . . . can still fill us with horror and pity, although that sensitivity is conditional. In an age where war has become a policy option rather than a last resort, where its legitimacy rather than its morality can be summed up on a sheet of A4 paper, we prefer to focus on the suffering caused by "them" rather than "us".

The tens of thousands of Iraqis killed in the 2003 invasion and subsequent occupation, the hundreds of thousands of Vietnamese killed in the Vietnam war, the hundreds of Egyptians cut down by the 1956 invasion of Suez, are not part of our burden of guilt. About 1,700 Palestinian civilians . . . equal to more than half the dead of the World Trade Centre . . .

were massacred in Lebanon.

But who remembers the exact date . . . 16-18 September 1982? "Our" dates are thus sacrosanct, "theirs" are not;

though "they" must learn "ours". How many times are Arabs pointedly asked for their reaction to 11 September, with the specific purpose of discovering whether they show the correct degree of horror?

And how many westerners would even know what happened in 1982?

It's also about living memory . . . and photographic records. The catastrophes of our generation, even our grandparents' generation, have a poignancy that earlier bloodbaths do not. We can be moved to tears by the second world war and its 55 million dead, by the murder of six million Jews, by our families' memories of the conflict.

I can understand why the Israelis have restructured their Holocaust museum at Yad Vashem. The last survivors of Hitler's death camps will be dead soon. So they must be kept alive in their interviews, along with the records and clothes of those who were slaughtered.

The Armenians struggle to memorialise their own 1915 Holocaust of one-and-a-half million at the hands of the Ottoman Turks because only a pitiful handful of survivors are still alive and the Turks still deny their guilt.

And here the compassion begins to wobble. Before the 1914-18 war, there were massacres enough for the world's tears; the Balkan war of 1912 was of such carnage that eyewitnesses feared they would never be believed. The Boer war turned into a moral disgrace because the British herded its enemies' families into concentration camps. The Franco-Prussian war of 1871 leaves us cold. So, despite the record of still photographs, does the American civil war.

We can still be appalled by the million dead of the Irish famine, although it is painfully significant that not a single photograph was taken of its victims. We have to rely on Illustrated London News sketches to show the grief and horror the Irish famine produced.

Yet who cries now for the dead of Waterloo, of the first Afghan war, of the Hundred Years' War, of the Great Plague? By the time we reach the slaughters of antiquity, we don't give a damn. Genghis Khan?

Tamerlane? The sack of Rome? Their victims have turned to dust and we do not care about them.

If, of course, the dead have a spiritual value, their death must become real to us.

Rome's most famous crucifixion victim was not Spartacus . . . although Kirk Douglas did his best to win the role in Kubrick's fine film . . . but a carpenter from Nazareth. And compassion remains as fresh among Muslims for the martyrs of early Islam as it does for the present-day dead of Iraq.

Anyone who has seen Shia Muslims honour the killing of Imams Ali and Hussein . . .

like Jesus, they were betrayed . . . has seen tears as fresh as those of Christians this week. You can butcher a whole city of innocents in the Punic War, but nail the son of Mary to a cross or kill the son-in-law of the Prophet and you'll have them weeping for generations.

What worries me is that so many millions have died terrible deaths because their killers wept over martyrs.

The Crusaders slaughtered the entire population of Beirut and Jerusalem in 1099 because of their desire to "free" the Holy Land, and between 1980 and 1988, the followers of the Prophet killed a million-and-a-half of their own after a Sunni Muslim leader invaded a Shia Muslim country.

Passion and redemption were probably essential parts of our parents' religious experience. But I believe it would be wiser now to reflect on the sins of our little human gods, those evangelicals who claim we are fighting for good against evil, who can ignore the oceans of blood humanity has shed and get away with it on a sheet of A4 paper.