Gustav may have done some damage to oil rigs and refineries in the Gulf of Mexico. At this point, that harm seems to be very modest. As the storm passed, oil dropped almost $5 to $109.

In the past, a natural disaster that could disrupt supply, a negative signal from OPEC, or a political problem in an oil-producing nation would have caused an oil spike that might have lasted for weeks.

Gustav may be the most significant indication yet that the dynamics of the price of crude have substantially changed. There are only a few reasons that this could happen. One is that the drop of oil and government investigations have pushed speculators out of the market. It was never clear how large their role was in the run that took crude above $140, but if they have moved to the sidelines the chances that oil would drop are probably enhanced.

The other explanation is one of simple supply. Almost all evidence points to Americans driving less and airlines flying less. It appears that a slight slowing of the economies in China and India has decreased their use some as well. The Bush administration said it was prepared to increase supply out of the Strategic Oil Reserve if Gustav had hit production hard.

Odds are the global economy will continue to cool. If so, the recent changes in the dynamics of oil prices are likely to continue to take the cost of the commodity back toward $100.

Douglas A. McIntyre is an editor at 247wallst.com.