The only silver lining in the War on Terror is that our enemies are primitives who believe that striking the NYSE or Citibank headquarters or even the IMF or the World Bank would have major economic consequences. We will win because they don't get it. We are economically (and spatially) decentralized. More than they can grasp. Terrible as the loss of life and the psychological hit would be, the economic consequences would be minor.
The World Trade Center Towers were tall and auspicious because of New York politics. They had no economic rhyme or reason. Losing them was a terrible loss of life but had little economic consequence. In fact, no major natural disaster in U.S. history (not Hurricane Andrew, not the Northridge Earthquake, nor any other that I can think of) had significant economic impact.
The primitives don't get it. Indeed, they cannot grasp the essence or the durability of decentralized systems. They are, after all, primitives.