Osama bin Laden, the Saudi-born revolutionary who is believed by most Arab and Iranian observers to be the inspiration of the attacks in New York and Washington, is the best known of the Islamic militants to have emerged in the past 20 years and the least difficult to fathom.

The prevailing ideology of the modern west - which is political economy - is in the doghouse. Having failed to notice atmospheric pollution, the economists then frightened themselves with the sort of financial crisis they said they had abolished.

Governments of rich countries spend some $6bn of tax money a year on disaster relief and development aid overseas, while each new earthquake, famine or tidal wave can attract 1,000 aid organisations, from the United Nations Children's Fund and Oxfam to the 'Jesus Brigades' of the American south and other charitable adventurers.

Viewed from a distance, or through the eye of the All-Knowing CEO of the Universe, the crash of 2008 followed the usual pattern. A long-lived boom driven by cheap credit, going back as far as 1982 (though subject to interruptions in the mid-1980s and 1990s, and in 2001), came to grief because of a rise in the cost of borrowing money.

Since the attack on the United States on September 11 2001, and the US retaliation in Afghanistan and Iraq, there must be few people who have not felt a twinge of nostalgia for the cold war.

In rising financial markets, the world is forever new. The bull or optimist has no eyes for past or present, but only for the future, where streams of revenue play in his imagination.

Of all the failed technologies that litter the onward march of science - steam carriages, zeppelins, armoured trains - none has been so catastrophic to prosperity as the last century's attempt to generate electricity from nuclear fission.