Tempting, but ... no.

As public fears of terrorism meet public and corporate irritation at high intensity security checking for air travellers, calls for "passenger profiling" grow louder and more insistent.

The argument appears appealing at first sight: why expend resources and public goodwill in checking everyone, when incidents thus far (actual or prevented) have been perpetrated by young men of one religion and one ethnicity? Why not concentrate on that population subgroup, gaining both resource efficiency and resource volume at the point of application whilst allowing everyone not in the profile to get on with their lives unimpeded?

Two very different answers to that "why not?" question are regularly aired, usually separately. There are others, and one in particular, which don't get much discussion time.

The first common answer is that this is morally unacceptable racism. It's a very valid answer, and I agree with it one hundred percent. It also has a utilitarian side. Tony Blair's continual assertion that grievances against Britain and/or the west are entirely spurious, whether true or false, is irrelevant: people feel grievances, regardless of whether we believe in them or not. Those who commit acts of terrorist do so (as archbishop John Sentamu recently pointed out) not because they are of a particular religion but because they feel alienated - and feelings of grievance will only exacerbate feelings of alienation. There is already enough prejudice in western societies to aggravate both; and marking out a subpopulation for increased suspicion, surveillance and hassle is hardly going to ease matters.

The second reason is that it won't work, because as soon as attention is directed towards one identifiable profile, the terrorists will choose individuals outside that profile as their active instruments. This, too, is a valid argument with which I agree. After a very short time (probably no more than a few weeks) profiling will reduce or even nullify, not increase, the effectiveness of security measures. Even at the most basic level, it's not hard to imagine a variation on the old "kidnap the bank manager's wife" ploy: it would not take very much duress of that type to induce an individual outside the profile to deliver a package.

A third reason, it seems to me, is philosophical. If we allow what chief superintendent Ali Desai, of London's Metropolitan Police, described as "...a new offence in this country called 'travelling whilst Asian'...", we have on one hand given the terrorists a prize and on the other hand partially relinquished our claim as a society to be morally superior to the terrorist. Once we agree to profile some subset of human beings on any basis other than criminal actions, we have in principle abandoned all the central tenets of liberal democracy - and with those tenets gone, what exactly are we defending?

I'm not blind to the appeal of the profiling argument. I just reject it, on every front.