At the time of writing, Tokyo still stands. Certainly, Shoko Asahara, leader of the Aum Shinri Kyocult, has been proved wrong in his prediction that something cataclysmic would happen last Saturday. Asahara now seems to be playing the longer mind game, and concentrating on his prediction that the world will end in 1997. Neurosis in Tokyo about that claim has been helped by reports that a diary seized from a cult follower included a price list for Russian nuclear weapons. Asahara, the Japanese now fear, may be a prophet of the self-fulfilling kind.
There are two possible lines to be taken on the mass terror that descended on Tokyo this weekend. The first is that it was peculiar to the Japanese psyche and topography: that the cult was exploiting a naturally superstitious people living in a country with a history of natural disaster. The other - and, I think, the more fruitful - line is that there are general lessons here about the psychology of terrorism. In fact, the main, and rather startling, moral is that the only real defence of society against terrorism is a reliance on the better nature and self-interest of the terrorists.
What the Asahara cult achieved in Tokyo on Saturday was a perfect piece of psychological terrorism. This tactic will only work if the society targeted has reason to believe the threat. Classically, after one or two real bombs, a terrorist group is able to cause as much chaos, without the risk of sympathy-eroding bloodshed, with a bomb rumour or bomb scare as with an actual device. The IRA, for example, could eventually bring London or Belfast to a halt for the price of a phone call.
In Japan in recent months there had been a devastating earthquake, followed by the most sinister act of terrorism in the history of the art: the release of nerve gas against civilians on the Tokyo subway, killing 12 and affecting 5,000. If ever there was a society in which a madman shouting on the street corner that the sky was falling could be guaranteed an audience, then Japan was it. Asahara - whose Aum cult is heavily suspected of carrying out the nerve gas attack - had only to mutter about a catastrophe on Saturday 15 April and hundreds of thousands of people would be hiding under their beds. There is a certain brilliant neatness in what Asahara achieved. Four weeks after Tokyo commuters were paralysed with nerve gas, he achieved a kind of mental paralysis of the whole of Tokyo, without actually releasing any gas.
The real surprise is that it has taken so long for such an incident to happen in a modern city. Madmen poisoning the water supply, the food source or releasing nerve gas into the atmosphere have featured in the thriller novel since the Fifties, but, perhaps because readers did not find the possibility convincingly chilling, most fictional madmen have been given nuclear weapons, which were a more plausible doom to the Cold War generation.
During the Gulf war, there were regular rumours in America of Iraqi terrorists being arrested by the FBI on the very brink of tipping vats of poison into the central reservoirs of New York, Chicago and Los Angeles, but there have been no resulting trials for such acts. (My conspiracy theorist friends assure me that the terrorists were quietly executed to avoid public panic.)
In fact, none of the more lurid projections of terrorist activity against the West has ever been fulfilled. Edward Heath once wrote with wry indignation of President Nixon bringing his own bottled water to Chequers because the Secret Service was worried about the security of a spring near the Prime Minister's retreat. But Nixon forgot himself, drank a glass of Buckinghamshire tap water, and lived another 25 years.
Millions cancelled air tickets in the months around the Gulf war, on the expectation that jumbos would regularly be exploded by Arab groups, but all those who flew landed safely. Relatives of the Lockerbie bombing would not, of course, share this optimism, but, even in that case, common predictions at the time that the destruction of Pan Am flight 103 would be followed by regular attacks on civilian aircraft have proved to be wrong. In general, terrorism has been a dog that didn't bark.
There are two possible explanations for this. One is that airline security has been hugely improved and that our governments are discreetly spending millions at sensitive installations such as reservoirs on armed guards and poison filters. But anyone who travels regularly by plane will suspect that another Lockerbie could easily happen if terrorists or their state sponsors really wanted it to. There must be something else that has prevented incidents such as the Tokyo nerve gas attack from happening before.
The answer is, I think, that we have so far been lucky (all these terms are relative) with our terrorists. They have tended to have a political aim. They have relied on sympathy and support within a community, and funds and sympathy from another part of society. The IRA and animal rights campaigners - the two terrorist groups active in Britain in recent decades, though not directly comparable in method or effect - fit this profile exactly. The IRA's language of "legitimate" targets and "regret" when "innocent" people died may have been morally and linguistically outrageous, but it was an acknowledgement of a deliberate gap between terrorist potential and terrorist action.
The bombs at Harrods and Enniskillen, the IRA's two biggest civilian outrages, both set back its cause considerably. Similarly, even the more fanatical animal rights campaigners probably understand that tipping poison into a reservoir, even if it were practically possible, would be a risk to the movement in PR terms. In short, terrorists, even when they are theoretically anarchists, have usually been constrained by societal manners.
Even state terrorism has been to some extent restricted, not by community morality but by community reality. Iran might have targeted a random 747 but went for an individual citizen, Salman Rushdie. This isn't much comfort if you are Salman Rushdie, but, even here, the one small hope of amelioration of the Rushdie situation involves EU economic pressure on Iran; of guarantees exacted in exchange for trade. Iran has come to see that terrorism has social consequences. Similarly, Syria and Libya discovered that suspicion of involvement in Lockerbie was a bigger liability abroad than it was a help at home.
Hence the most terrible threat comes from terrorists who don't care about how it might play on the evening news or in next year's fund-raising (for small factions) or trade negotiations (for terrorist states). It has been common for British politicians to say, of the IRA, that they had "a total contempt for human life". But, in fact, the world has so far dealt mainly with terrorists who had a selective and PR-conscious contempt for human life. Only now are there signs that those with total contempt may be arising. And that is the lesson of Shoko Asahara, who thinks the world will end in 1997, and may be planning to make sure it does.