Nonetheless it is widely held that Christianity is the religion of peace; Moses's face has been 'turned to the wall, Mother' and everything awkward supposedly said by Jesus is, of course, symbolic; as we all understand, there is no more subtle description of 'chalk' than to call it 'cheese'.

The peaceful bits of the New Testament are prominent in the popular mind: "blessed are the peacemakers", "resist not evil", "turn the other cheek", "love your enemies" . . . are the textual staples of many Christian pacifists among whose ranks have been numbered many brave and admirable people. This pacific element being so prominent in scripture, it was realised a long time ago that some credible way of having your cake and eating it was required if Christianity were to have the backing of the rich, the powerful, the ambitious and the fanatical - the backing of those very persons whom, it might be supposed, Christianity was intended to resist in God's name.

Realpolitik generated, primarily through the pen of Thomas Aquinas, the theory of Just War. This theory holds that it is just to go to war if certain criteria are met; they are: 1) There must be just cause, 2) Every reasonable attempt must have been made to settle the issue without bloodshed, 3) War must be declared by legitimate authority, 4) The damage and suffering caused is likely to be less serious than the wrong it seeks to right, 5) Success must be likely (if having been scrupulous about the first four criteria, you then lose the war, you have achieved the worst of all worlds). The final requirement is 6) Treat the defeated enemy with magnanimity.

These tests of the justice of war are by no means nonsensical; most of us would still claim that the anti-Gernan War 1939-45 met these criteria - the subsequent failure to make the world a fundamentally better place notwithstanding. The chance to do so was there and not the less so for its having been largely wasted.

It has to said that these criteria can be applied to belligerent causes that many of us might deem unworthy and much the same practical ambivalence is true of many of the other products of that most addictive of parlour games - theology. Let us, for example apply the Aquinas criteria to the initial phase of the recent Gulf War - the Iraqi takeover of Kuwait.

Under 1), it could be argued that many of the frontiers in the region were drawn by self-interested Europeans and that these frontiers, unjustly, separated Arab from brother Arab. The Iraq-Kuwait border could scarcely be seen otherwise, it could be claimed. Under 2), The Iraqis had been talking about the issue for a long time and their case had not been argued against in any concerted and coherent way. On the contrary, the State Department had given a visible green light to Saddam. Under 3), the Bagdhad government was as legitimate as any - which may or may not be saying much; it enjoyed both diplomatic recognition worldwide and the supply of weapons from many countries including precisely those who drew the disputed frontier in the first instance. Under 4), there has to be some room for difference of opinion but evidently the damage and suffering need only have been slight as, considering 5), the Iraqis moved in very easily indeed.

Subsequent events notwithstanding, Saddam Hussein and his friends are still in power enjoying wide support among the Arab peoples - which is more than can be said of Thatcher, Mitterand, Gorbachev and Bush among their peoples.

It would demand very little of the persuader's art to convince many Arabs that Saddam's having met the Aquinas criteria, and having been unjustly attacked for succeeding in an exercise based upon them, is still there because Saddam has acted, in trying circumstances, in a way pleasing to Allah.

We have heard rationalisations less tenable than that and even if people think, as I do, highly unfavourably of Saddam and his works, we would be well advised to sell our Aquinas stocks before their value goes through the floor. We need to base peace or war decisions on something less pliable than classical Just War Theory.

One day, someone will write a book on Just Abortion; it might be a better effort than anything old Aquinas ever thought of. Come on JP2 - be a devil!