SOME GLIMMERS of good news are finally beginning to emerge from the rubble and despair of New Orleans and the other areas devastated by Hurricane Katrina. But the infuriating, unmistakable and unnerving lesson of the continuing tragedy is the fundamental failure of government at all levels to protect its citizens, the most vulnerable chief among them. Granted, the "ultra-catastrophe" of Katrina, as Homeland Security Secretary Michael Chertoff put it -- the devastation of an entire city, its communications, power, transportation and other infrastructure; the dislocation of hundreds of thousands of people -- is beyond anything the nation has ever dealt with. Still, coming four years and tens of billions of dollars in preparedness spending after the Sept. 11 attacks, it suggests that the country's readiness to cope with a major disaster remains woefully lacking.

The governmental failure exposed by Katrina is multilayered and long-standing. It begins with the shortsighted decision not to confront the inescapable geographic reality of a city built largely below sea level. Every disaster brings in its wake the inevitable exhuming of obscure reports warning of shortcomings and the inevitable second-guessing about money that could have been spent to prevent it. But in the case of Katrina, the precarious situation of New Orleans was well-known -- the Federal Emergency Management Agency in 2001 put a hurricane in New Orleans among the top three most catastrophic events the country could face.

New Orleans faced a clear and present danger from the combination of sinking land, rising sea levels, and the rapid shrinking of wetlands and barrier islands, which served as a buffer to hurricanes by sapping their energy and absorbing sea surges. Addressing this problem would take an enormous sum, $14 billion, and any fix wouldn't have happened in time to spare the city from the effects of Katrina. But the Bush administration, instead of grappling with the problem, resisted attempts to remedy it; as recently as this summer the White House was fighting -- unsuccessfully -- an effort to spend $1 billion to rebuild coastlines and wetlands. Similarly, rather than supporting efforts to buttress the levees that are supposed to shield the city, the administration consistently worked to cut funding that could have helped build up those defenses.

Given the known risks, the response of government -- local, state and federal -- to the approaching storm was inadequate, uncoordinated and inept. Despite President Bush's assertion that no one could have anticipated that the levees would fail, officials were well aware that the levees could be counted on to withstand only a Category 3 hurricane, not a Category 4 storm such as Katrina. Under those circumstances, where was the contingency plan for personnel and equipment to contain a breach?

Similarly, a mandatory evacuation order was in no way a sufficient response to Katrina's impending arrival; it was clear that a significant number of New Orleans residents would remain -- many because they had no alternative. Where were the buses or other vehicles to help them leave? Where was the plan to avoid the bedlam that developed in the Superdome and the convention center? How could it have taken four days for National Guard troops to arrive to restore order in the anarchic city?

Some of the basic weaknesses exposed by Sept. 11 -- and, one would have presumed, since fixed -- seemed instead to linger. For example, police and other officials were unable to communicate as their cell phones failed and satellite phones took days to arrive. It took until late Tuesday, long after the storm hit, to declare "an incident of national significance," a designation that gave the federal government extra power to deal with the escalating crisis.

Indeed, the hard question that must be asked is whether the absorption of FEMA into the Department of Homeland Security bureaucracy, and the natural focus of DHS on the terrorism threat, actually diminished the agency's capacity to respond to a natural disaster such as Katrina by draining attention, personnel and dollars from such events. FEMA, said one official, was "completely dysfunctional and completely overwhelmed" with "no coherent plan for dealing with this scenario." The official was no foe of the administration but Louisiana's Republican senator, David Vitter. FEMA's director, Michael D. Brown, appears out of his depth.

The vulnerability of New Orleans to a major hurricane was well-known; the path and force of Katrina were charted for days in advance. If the response to an anticipated risk is so poor, what, then, would happen in the face of a surprise event such as a bioterrorism incident or nuclear attack? Katrina is, in that sense, an ill omen in addition to a disaster in its own right, one whose lessons must be faced once the immediate catastrophe has been addressed.