On 27 February, the Times ran an extraordinary story which has not been reported elsewhere. Newly released papers from the Public Record Office show that, in the early 1960s, Ministry of Defence scientists released spores of the microbe Bacillus globigii on London's Northern Line trains. The aim was to test "the viability of vegetative organisms in the Underground air". What is alarming is not so much the potential danger to London commuters - the bacterium, or so we are told, was harmless - but the apparent reason for the tests. This was not to monitor possible effects of an enemy attack on London, but to assess the feasibility of a British attack on other countries' underground systems. The bacterium, which has the same spore size as anthrax and had been obtained from America, "appeared a most promising agent", the official papers recorded.
This tale is a timely reminder that the manufacture of weapons of mass destruction, and the willingness to contemplate their use, is not confined to the likes of Saddam Hussein. The US, after all, had the nuclear bomb (and had used it, moreover) before Soviet Russia, and as Professor Peter Hennessy records in his new book, The Secret State, British intelligence in the late 1940s reported a US view that "we have the bomb; let's use it now while the balance is in our favour". This attitude, horrifying as it now seems, is not far from the justifications for the proposed attack on Iraq: overthrow Saddam before he has the weapons that will make him a real danger.
So is there a moral equivalence between "our" willingness to use lethal weapons and "theirs", whether "they" be Soviet Russia or Iraq? Surely not. Christopher Hitchens, Martin Amis and others are right to argue (see John Lloyd's report, page 10) that regimes which arbitrarily imprison, murder and torture their own people on a large scale are likely to be just as ruthless towards the nationals of other countries. Nor is it wrong to pose the question: under which regime would you rather live? People try to get out of tyrannies but to get into democracies; and even those who said "better red than dead" during the cold war implicitly accepted that this was not much of a choice. The possession of weapons, in other words, cannot sensibly be separated from the aims they are intended to support.
But we cannot slide from this into a belief that war must be waged against any non-democratic country that threatens to make weapons of mass destruction. Even the US does not take this view, since it now treats Pakistan, a military regime that possesses nuclear weapons and has threatened to use them in a first strike against India, as a valued ally. There must be reason for thinking that the benefits of trying to overthrow the tyrant will outweigh the costs in human lives and destruction. The US may have intelligence on Saddam Hussein's intentions that are not available to the public; but there are few other grounds for seeing him as an imminent threat. We could have more confidence in the US assessment if President Bush and his advisers did not flit from one target to another - Somalia, Yemen, Iran, North Korea, the Philippines and various bits of the Caucasus have all been threatened - like deranged men seeing demons in the night.
Saddam invaded Kuwait more than a decade ago; he was swiftly and rightly expelled. Since then, he has not stirred from his lair. He has not threatened attacks on Britain or America. Attempts to link him with the al-Qaeda network have failed. He is not a supporter of Osama Bin Laden or any other brand of Islamic fundamentalism; indeed, the steadfastly secular nature of his regime makes it exactly the sort of thing the Americans would normally support.
The most immediate effect of an American invasion (or even the threat of one) would be to persuade Saddam to use whatever lethal weapons he has, possibly against Israel. The longer-term effect, particularly given the US failure to nurture a plausible alternative government, would be further to destabilise the Middle East; to drive more young Arabs towards extremist Islam; and to persuade other Middle Eastern and third world countries that they had better acquire nuclear weapons to protect themselves. Quite possibly, the US government does not care about any of this, believing that, since its military power is now so much greater than anybody else's, it can subjugate half the world if necessary. But the British government should care, and it should use its much-vaunted special relationship to counsel restraint.
Since 11 September, we should remember, there has been no further significant attack on America or Britain, save for Richard Reid's lone attempt to hijack a transatlantic flight just before Christmas, which has still not been definitively linked to any terrorist organisation. The anthrax parcels, it is now almost certain, were weaponised within the US, by an American scientist. (This usefully reminds us that the US itself remains the biggest source of weapons of mass destruction and that there is always a chance that these, too, could fall into the wrong hands.) All reports of imminent further attacks - like the claim that terrorists were about to smuggle a ten-kiloton nuclear weapon into New York City - should be treated with scepticism, as should claims from European security forces that they have routed yet another cell of swarthy young men and found maps, knives, spades and plans for underground tunnels lying conveniently on their bedspreads. Desperate for funds and public esteem, police and intelligence agencies will not bother to make too fine a distinction between truly dangerous terrorists and amateur pranksters.
In the end, when it comes to lethal weapons, there may not be as much difference as we like to think between tyrannies and democracies. In both, the big decisions will be taken, away from the public gaze, on the advice of unaccountable and often blinkered military chiefs. And in both, fear, shading into paranoia, will be the main motivator. We must hope, in these perilous times, that an understandable paranoia does not lead America into a reckless and potentially disastrous adventure.