This is the phrase repeated again and again when Katrina broke through the levees of denial: "I can't believe this is America."

The mantra of disbelief echoed from a veteran of the war in Afghanistan to the president of Jefferson Parish, to mothers and fathers in the Superdome to families around their television sets: "This doesn't happen here."

For days on end, we watched a toxic gumbo of natural and man-made disasters cooking along the Gulf Coast. "The city that care forgot" felt forgotten. The "left behind" were not characters in a faith-based thriller, but old folks, poor folks, black folks without enough money to pay for a ticket out of hell.

For a time, reporters called them "refugees" as if the displaced citizens of the late, great city of New Orleans were Bosnians or Somalians. For a moment, an exhausted Brian Williams, embedded in the Superdome, talked about getting back to the states as if the sports arena was a foreign country. "I've seen things," he said, "I never thought I'd see in the United States."

Now, in the parade of plagues, flood is followed by fire and pestilence. Words like "diaspora" are used to describe an exodus of biblical proportions.

And tomorrow we will mark the anniversary of 9/11, not merely with a bizarre country music festival planned by the Pentagon, but with mourning and cleaning.

It's been four years since al-Qaida came crashing out of the blue, shattering the threshold of our imagination. As men flew planes into buildings, as innocents fell to their deaths, we were left gasping at our vulnerability. This year, Katrina has come out of the Gulf and left us gasping, not at evil but at incompetence, not at sworn enemies but at sworn protectors.

Forgive me if I find some comfort in the voices that expressed shock and shame that "this" could happen in our own country. They were not shocked by the hurricane, however devastating. They were not shamed by the flood or even the evacuated city. The disbelief was about people stranded for days on rooftops, abandoned in a sports stadium, unprotected in hospitals, drowned in nursing homes.

The disbelief was that while "this" happened, FEMA fiddled, a ship sat idle in the Gulf of Mexico with 120 sailors and 600 hospital beds, and the president expressed the tone-deaf optimism that Trent Lott would rebuild a "fantastic" new home from his rubble:

"I'm looking forward to sitting on the porch."

The chorus of horror at the abandonment expressed a wounded sense of who we are as a people and who we are not. And that brings some small comfort to those of us who have felt increasingly like strangers in the country we knew.

Throughout the Bush II years, how many of us have thought in less dramatic moments, "I can't believe this is America"? When the White House dismisses global warming even while the waters eat away at our shores. When the number of poor people keeps rising and the administration targets healthcare funds for cuts and Social Security for "reform." When we are up to our ears in Iraq and debt and the White House wants to kill the estate tax for the heirs of the wealthiest.

Now, finally, more of us look into the mirror of Katrina and see something foreign to our sense of self.

Historians will tell you that the American self-image is woven from the warp of individualism and the weft of community. Individualism makes us applaud those who stand on their own two feet, pick themselves up by their bootstraps, go get 'em. The sense of community makes us reach out to those in need, and, yes, see the government as the strongest rescue vehicle for our mutual aid society.

"In America, we do not abandon our fellow citizens in their hour of need," said the president, finally, between complaints about the "blame game." But that's what he has done repeatedly. His White House pays lip service to compassionate conservatism while looking at government as the "beast to be starved." Now, in disaster, we all remember the need for this beast of burden.

I remember what the president said during a campaign debate in one of his endless attempts to link 9/11 to Iraq: "I have a solemn duty to protect the American people." Abroad in Iraq, that duty is shaken to the core. At home in the Gulf, that duty was devastated.

And now, with empathy and anger, with generosity and dismay, we begin the long and uncertain recovery for the victims of Katrina and for the belief in America.

Ellen Goodman is a Boston-based writer on modern social issues.