Like many seismic events, Katrina’s true impact might take a while to absorb. What started as a natural disaster soon became an unforeseen social meltdown and potential political crisis for the president. The poverty, anarchy, violence, sewage, bodies, looting, death and disease that overwhelmed a great American city last week made Haiti look like Surrey.

The seeming inability of the federal or city authorities to act swiftly or effectively to rescue survivors or maintain order posed fundamental questions about the competence of the Bush administration and local authorities. One begins to wonder: almost four years after 9/11, are evacuation plans for cities this haphazard? Five days after a hurricane, there were still barely any troops imposing order in a huge city in America. How on earth did this happen? And what will come of it?

In the past, American disasters have led to political changes — the Johnstown flood in 1889 and the Galveston hurricane in 1900 led to fury at class privilege and a government that seemed not to care for the poor. The 1927 flood in New Orleans — and the inequalities it exposed — propelled the rise of the populist demagogue Huey Long.

There seems to me a strong chance that this calamity could be the beginning of something profound in American politics: a sense that government is broken and that someone needs to fix it.

It did, after all, fail. It failed to spend the necessary money to protect New Orleans in the first place. This disaster, after all, did not come out of the blue.

Below is a passage from the Houston Chronicle in 2001, which quoted the Federal Emergency Management Agency on the three likeliest potential disasters to threaten America. They were: an earthquake in San Francisco, a terrorist attack in New York City (predicted before 9/11), and a hurricane hitting New Orleans.

Read this prophetic passage and weep: “The New Orleans hurricane scenario may be the deadliest of all. In the face of an approaching storm, scientists say, the city’s less-than-adequate evacuation routes would strand 250,000 people or more, and probably kill one of 10 left behind as the city drowned under 20ft of water.

“Thousands of refugees could land in Houston. Economically, the toll would be shattering . . . If an Allison-type storm were to strike New Orleans, or a category three storm or greater with at least 111mph winds, the results would be cataclysmic, New Orleans planners said.”

Katrina, of course, was category four.

So what was done to prevent this scenario? There was indeed an attempt to rebuild and strengthen the city’s defences. But the system of government in New Orleans is byzantine in its complexity, with different levees answering to different authorities, and corruption and incompetence legendary.

More politically explosive, the Bush administration has slashed the budget for rebuilding the levees. More than a year ago, Walter Maestri, emergency management chief for Jefferson Parish, Louisiana, told the New Orleans Times-Picayune: “It appears that the money has been moved in the president’s budget to handle homeland security and the war in Iraq, and I suppose that’s the price we pay. Nobody locally is happy that the levees can’t be finished, and we are doing everything we can to make the case that this is a security issue for us.”

It’s still unclear whether even with higher levels of funding the levees would have been strong enough to withstand Katrina in time. The Army Corps of Engineers has backed the president and said that the levees were built for only a category three hurricane and were in satisfactory shape. But levees need constant maintenance and an agency with a one-year budget cut of $71m might have skimped. The connection between shifting funds to fight wars abroad rather than to defend against calamity at home is a politically explosive one. As one Louisianan said: “You can do everything for other countries, but you can’t do nothing for your own people. You can go overseas with the military, but you can’t get them down here.”

To make matters worse, thousands of Louisianan National Guardsmen, who might have been best able to maintain order, are deployed in the deserts of Iraq, in a war that is increasingly unpopular. Again: it’s hard to know if this really would have made a huge amount of difference, but the argument has the force of a category five political storm.

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