By Andrew Walker BBC News economic correspondent

The World Trade Centre was the consummate symbol of global capitalism. No doubt that's why Al Qaeda chose it.

The events of September 11th sent shudders through global financial markets and raised the spectre of a global recession.

In the end, the economic consequences of those terrible events weren't as severe as many people feared. But it was a very uneasy ride.

Even before that morning, the economic context was clouded.

For the previous decade, the United States had been the dominant driving force of the international economy.

Long boom

The US boomed through the 1990s.

Market falls have done more damage than terrorist attacks

When there was a wave of financial crises in the developing world - Asia, Russia and Brazil from 1997 to 1999 - the US steamed on, providing a market for the rest of the world, especially for the Asian countries recovering from their crisis.

And then, in late 2000, the US started to falter. So did much of the rest of the world.

In 2001 stock markets fell, businesses cut back on investment. By the time of the attacks, the US economy was near to recession.

In the judgement of the National Bureau of Economic Research - which has a committee of academic economists who pronounce on these matters - the attacks were the final blow tipping the US over the edge into recession.

Immediate effects

There was an immediate effect on business.

The stock exchange closed. The airlines stopped flying altogether for a few days. People stayed in, glued to their televisions.

And then, when the stock market reopened after a week, the Dow Jones Industrial Average index of leading stocks plunged 15%.

There had already been heavy falls in European stock markets, where business had continued.

Personal wealth was hammered, which could easily have left people unwilling to spend, wreaking economic havoc.

It didn't work out quite like that.

Rate cuts

The central banks rode to the rescue, led by Alan Greenspan and the Federal Reserve, with a succession of interest rate cuts.

The Fed made four cuts by the end of the year, bringing its main rate down to 1.75%.

It seemed to work.

US national income started to increase again by the end of the year.

And the stock markets rebounded too.

The US certainly had a recession last year. But it seems to have started recovering late last year or early in 2002.

Global fall-out

Defining a global recession is more complex.

Falling total incomes are very rare on a global basis.

Many developing countries have a much faster underlying growth rate - partly to keep pace with increasing population.

The overall conclusion of the International Monetary Fund is that there wasn't a world recession, but it was a close call, with world growth at its lowest level for a decade.

So is the panic over?

Not necessarily.

The worry now is the falling stock markets, sent reeling by a succession of revelations about misleading company accounts of companies like Enron and Worldcom.

It has led to uncertainy by shareholders who wonder what they can believe. And a share is essentially the right to a cut in the company's profits. So if you don't know what the profits are, how on earth do you know what the shares are worth?

A double dip recession?

It is, to date at least, primarily an American problem.

Even so it gave a real scare to investors in Europe and Japan, where markets have also been hit hard.

And it made many fund managers more reluctant to take on investments they think are risky - notably in developing countries' markets.

So a little fiddling of the books in the US has some serious repercussions around the world.

As for the economic impact, so far there is not much sign that the latest share price falls have persuaded American consumers to draw in their horns.

The strong housing market means that personal wealth hasn't been hit as hard as it could have been.

So the US and global economies continue to do better than the stock market.

It might - with luck - stay that way. But what if the stock market turmoil sets off another deterioration in the wider global economy?

What an irony it would be.

The economy reeled but ultimately stayed on its feet after a deliberate assault from an organisation driven by hatred of the world's most capitalist nation.

Now global capitalism is having to fight off an internal malfunction that is proving to be just as corrosive.