As war begins, financial authorities are implementing plans to insure that commerce continues. The first measures will probably be heightened vigilance, rather than the immediate action of coordinated interest rate cuts by key central banks that took place after September 11. For now, the markets seem to be holding up well, with stock prices rising and oil prices falling, but this could change quickly if there are terrorist attacks.
See "Officials set for war on the financial front", Eric Pfanner, International Herald Tribune, March 19, 2003