"There is on the globe one single spot, the possessor of which is our natural and habitual enemy. It is New Orleans, through which the produce of three-eights of our territory must pass to market."

 So wrote Thomas Jefferson in 1803 to his negotiators in France, in words intended to persuade Napoleon to sell the already thriving port city to the young United States. The French ruler was impressed enough to throw in the vast hinterland of the Louisiana Purchase, all for the bargain price of $15 million.

 As I write, four days after the levees broke, the possessors of New Orleans are the waters and the looters and thugs who have been plundering luxury merchandise and shooting at policemen and rescue teams. The criminals seem likely to be dispersed by the soldiers now pouring into the city, and the floodwaters will in time -- it will seem an agonizingly long time -- be displaced. But the question will remain: What kind of New Orleans will be rebuilt?

 It could just be an industrial terminal. George Friedman, of stratfor.com, argues that "the ports of South Louisiana and New Orleans, which run north and south of the city, are as important today as at any point during the history of the republic." As in Jefferson's time, this "is where the bulk commodities of agriculture go out to the world and" -- we get beyond 1803 here -- "the bulk commodities of industrialism come in." Those bulk commodities include oil and natural gas, about one-quarter of the national production of which come through New Orleans and South Louisiana.

 Friedman's argument seems hard to counter. And it is surely within the nation's physical and financial capacity to rebuild New Orleans' port and oil infrastructure -- re-engineering it to withstand a Category 4 or 5 hurricane this time, not just a Category 3 -- and make it once again what it was until last weekend. But ports and petrochemicals are no longer labor-intensive industries: It doesn't take that many employees to man a refinery or a container port. Port Fourchon, the site of the Louisiana Offshore Oil Port, is a tiny community in southern Lafourche Parish. Restoring the port will not restore the fabric of the city.

 And some parts of that fabric are not worth restoring. The city of New Orleans has had a horrifyingly high crime rate in recent years, and after disaster hit, the reports of looting -- not just of food and necessities, but of luxury items -- have been rampant. Shots have been fired at rescue teams and police officers; supplies of food and medicines on their way to hospitals have been hijacked; gangs of criminals have stolen boats from survivors. Flooding has produced an urban riot like those of the 1960s or Los Angeles in 1992.

 I worked as an intern in the office of the mayor of Detroit during the riot summer of 1967, and I know what happened to that city during the riot and after. The riot destroyed some commercial strips, but the high crime that persisted for years afterward resulted in the emptying out of large parts of the city, the destruction of the value of commercial and residential real estate, and a population drop from 1,670,000 in 1960 to 900,000 in 2004.

 Something similar has been going on recently in New Orleans. The population of the central city declined from 484,000 in 2000 to 462,000 in 2004 -- one of the biggest percentage declines in the nation. It seems unlikely that many of the small wooden houses in neighborhoods dominated by the criminal underclass will be habitable after the waters recede, nor will it be worth anyone's money to rebuild them. New Orleans may suffer a population loss similar to Detroit's in a much smaller period of time.

 The suburbs are more likely to be rebuilt, and the gambling casinos and the historic structures of the French Quarter and the Garden District will be, too, to the maximum extent possible. The tourist trade, which has recently been New Orleans' biggest employer, will likely revive, and the city's great restaurants will likely reopen.

 But New Orleans' heritages of upper-class complaisance and political corruption -- the result of the city's French tradition -- work against a more broadly based commercial and economic revival. Without changes in these attitudes, historic New Orleans may revive, but the city will become little more than a theme park, like Venice, and not the great commercial beehive it once was.