The Bush administration has already committed enormous sums of public money to stabilizing the financial system and staving off economic collapse, but it looks like more — much more — is going to be needed. Economists have come around to the view that a second big fiscal stimulus is required, and soon. The main question is just how big.

The crisis until recently has had an air of phony war about it. The financial industry has been devastated and governments have stepped forward with interventions that would have been difficult to imagine even months ago.

Yet for most people in the rest of the economy, things seemed to be carrying on much as before. The nonfinancial economy was muddling along. This did not feel like much of a recession, still less like the onset of a new Great Depression. Suddenly, however, the implications of the financial meltdown are feeding through.

Most important, the stunning fall in stock markets at home and abroad, and the continuing volatility and uncertainty, are at last affecting consumers’ spending plans. It takes a lot to discourage consumers in this country. (Having an income that falls persistently short of expenditures is not enough to do it, for instance — which helps explain how we got into this mess in the first place.) The financial mayhem of recent months has finally made an impression.

This week, we learned that consumer confidence crashed in October to its lowest level since records began more than 40 years ago. This is far more worrying than a run of bad days on Wall Street. So severe a collapse in confidence — forecasters had expected a big drop, but not this big — is invariably the leading edge of a major recession, and unless governments act promptly and wisely, maybe a very prolonged one as well.