We must not allow our desire for revenge lower our moral standards

September 11: that's all you need to say, and everyone knows immediately what you mean.

No other catastrophic event in world history is labelled simply by a date - we may know exactly what we were doing when Kennedy was assassinated, when Kurt Cobain killed himself or when that airliner blew up over Lockerbie but very few people could identify the events by a simple mention of the dates.

This is yet another way in which the terrorist attacks on New York and Washington have changed the world.

Perhaps it's not the world itself that has changed - there have been mindless atrocities before, some of them on a scale as large as this - but our way of looking at it.

Helpless in the face of incomprehensible evil, we sense that the old moral certainties of the Western world can provide us with no answers.

Love will not find a way, turning the other cheek brings no respite, even giving in and surrendering makes no sense, because these terrorists make no demands, and it seems there is no way of appeasing them.

They are the joyful martyrs, we are merely their victims, and all they want is to destroy/punish/frighten us, and so our ethical system cannot provide us with an adequate way of responding.

As Jeremy Irons said in that brilliant but depressing film The Mission, "If might is right, then love has no place in the world".

No wonder that even ardent pacifists are rethinking their positions, and that the issue of capital punishment is raising its ugly head again. When there is no way of arguing with your oppressor, for many people the only way of responding is to lash out in blind hatred, no matter how futile that may be.

But we have to be careful. A demand for the death penalty for Amrozi very easily can extend to a hatred for all people who look like, worship in the same way as, live in the same country as him.

It's easy to fall into the David Oldfield trap and assume simply that because most terrorists are Muslims, most Muslims must, therefore, be terrorists - it may be a fundamental error in logic, but there's something comforting about it.

Absolute terror, absolute evil (and those are the terms in which we in the West see the events of the past two years) do demand a new way of thinking about how we deal with them. But it's not the first time that people in the West have had to face this moral issue.