MANY questions arise in the aftermath of September 11. Some can be answered while others remain the imponderable stuff of philosophy.

In the wake of such terror, it is fair to ask if religion offers any balm. Certainly, there was something Biblical about the terrorist atrocity, not in how or why it was carried out, just in the enormity of its scope, with so many dead in so few moments, obliterated by a modern plague.

To those of us without religion, or at least nothing you could put a finger on, the terrorist atrocity was the ultimate reminder that we won't be here for ever. So much is useful to remember, if hardly comforting.

Many of the words used have been Biblical, notably 'apocalypse' and 'Armageddon'.

The first refers to the end of the world; the second to the final battle between good and evil before the Day Of Judgement.

President Bush believes this is a final battle and he has saddled up with the good guys. He does have right on his side, as what was inflicted on America and the world was so unspeakable. But nothing is ever that simple, and a rightful crusade can still do wrong. Some Christians, so far as I understand it, point to the difference between justice and revenge. The first can be easily justified, while the second cannot.

Touching this distinction, it is difficult to see how bombing Afghanistan into oblivion will be anything other than blind revenge, punishing the innocent and the starving while doing little to harm the guilty.

The likelihood of striking out Osama bin Laden, the Saudi terrorist suspected of being behind the atrocity, in such a manner must be thin.

In the light of such global concerns, it might seem petty to worry about Home Secretary David Blunkett's suggestion that compulsory identity cards could be introduced in the fight against terrorism.

Yet we should always worry when a Government suggests bringing in a strict measure under the cover of a crisis.

It is easy at such moments to see the Government swirling a dark cloak over all sorts of rights and personal freedoms.

Of course, this is an issue to divide people. Supporters of ID cards will say there is nothing wrong in helping the police by being so readily identifiable.

Others will fret that the State is taking on too many powers, and that identity cards are 'un-British'.

This is not a simple, right-left matter. Doubting liberals such as myself - a free bleeding heart with every purchase - find themselves lining up with libertarian rightwingers in opposition to identity cards.

At a time like this, it is fair to ask if identity cards would have any effect in deterring terrorism.

This strikes me as extremely unlikely. How, for instance, do we confirm the identities of the estimated 80 million travellers who pass through our airports every year?

I wouldn't fancy that job myself.

Wartime identity cards were withdrawn by Sir Winston Churchill in 1953. This followed a ruling by the Lord Chief Justice, Lord Goddard, who, incidentally, was also in that year the judge in the Derek Bentley trial.

Lord Goddard observed that giving police the power to demand ID cards from "all and sundry" made people resentful of the police and "inclines them to obstruct the police instead of to assist them".

This remains an important point, for letting the police stop and question all of us, as if every one of us were a suspect, or at least suspicious, is hardly going to foster good community relations.

So whatever the imperative, I would say no thanks to ID cards.