PRESIDENT Bush and top Democratic presidential candidates will all visit New Orleans this week for the second Hurricane Katrina anniversary. Here's hoping one of them will be brave enough to say the truth: A family of able–bodied adults can rebuild a house on its own (even though it's hard) and help its neighbors do so—but a family can't build an effective police and prosecutorial force to protect it from criminals on its own.

The president's office likely will put out a fact sheet on how many billions of dollars have gone to Gulf Coast recovery; Democrats will no doubt call for more money and action. But tens of billions of dollars, past or present, can't fix the city.

To see how New Orleans is doing, consider two recent stories:

This past weekend, seven family members and friends were enjoying a quiet night outside their home in a tranquil neighborhood of the city's eastern region, which was badly flooded by Katrina. Their evening was interrupted when, according to New Orleans police, gunmen forced them into their house, herded them together and robbed them.

Then the robbers shot them all—killing two.

That was the second horrific crime in the same neighborhood in two weeks. Two weeks ago, gunmen killed a couple in a similar double murder (leaving unharmed their infant and toddler).

As The New Orleans Times–Picayune notes, other victims just have been luckier. "The slayings . . . were the latest in a series of armed home invasions and robberies in eastern New Orleans," wrote reporter Brendan McCarthy. "Several crews of gunmen . . . have robbed and shot workers . . . and homeowners in the area, where many residents are rebuilding their flood–damaged homes." Also just last week, gunmen lined up six home laborers and shot three of them, killing one.

Since Katrina, in fact, New Orleans has clocked a murder rate higher than that of any first–world city. Depending on estimates of the city's population, it's perhaps 40 percent higher than its pre–Katrina rate and twice as high as activities such dangerous cities as Detroit, Newark and Washington.

Families trying to rebuild must live in fear—or they don't come home at all. The two families brutally shot this month most likely did what many New Orleanians have done: gone ahead and rebuilt on their days off, using their bare hands. As Rev. Nguyen The Vien, the pastor of an eastern New Orleans church, told me on a February visit, "We're here, and we're rebuilding"—with competent government help or without.

Indeed, Nguyen and his parishioners seemed to treat any hope of federal money trickling down to them as almost an afterthought: fine to pay the bills, if it ever arrives, but not essential.

After Katrina, neighbors fixed up Nguyen's church under his direction so that they'd have a "home base" where people could eat, shower and sleep. Then they started rebuilding, house by house; they're still at it. Residents of many other neighborhoods—white, black and Asian—have done the same. As many New Orleanians have found out the hard way, this work is backbreaking, but it's not impossible.

But what New Orleanians can't do by themselves is make up for the city's long–broken attitude toward criminal justice. For generations, New Orleans has hobbled along without a real law–and–order presence. Criminals graduate from petty crimes to burglary to drug dealing to carrying illegal weapons to gang robberies to murder, and face few consequences.

The police and (in particular) the prosecutors are ineffectual. The mayor doesn't try to change it, because he thinks, as he often says, that it's a social problem—a lack of opportunity for poor young black kids.

The Bush administration has done a few things (though not enough) to attacks the city's intolerable crime problem, deploying extra federal law–enforcement agents to try to get the worst criminals off the street. (The state has also sent in the National Guard to patrol half–empty neighborhoods.)

But just as U.S. forces can only do so much in Iraq until the Iraqi government changes its attitude, the feds and the military can't do enough in New Orleans until its local government changes its attitude.

Mayor Ray Nagin and DA Eddie Jordan need to stand up and say, calmly, that people who commit crimes have to go to prison, so that their family members and neighbors can learn that criminal behavior has a rational, predictable negative consequence.

So far, they haven't. But the president can use our money—federal dollars—to try to convince them to.

In his speech in New Orleans this week, Bush should say that he's ready to ask Congress for $500 million for the city's police and prosecutorial forces over two years—but only if Nagin and Jordan make it their No. 1 priority to enforce the law rationally. And only if the city works with the feds to tie the money to measurable results, starting with rational arrests for offenses from quality–of–life infractions to homicide, more effective prosecutions and sentencings—and, ultimately, fewer crimes.

It's an enduring mystery why Bush hasn't used Katrina to show the world that America can rebuild a major city using bedrock conservative principles: law and order first.

Democrats could say the same, of course. Barack Obama, John Edwards and Hillary Clinton have all mentioned New Orleans' crime problem in recent speeches. But they often tie it to a post–Katrina lack of staff and equipment, as if it's a question of rebuilding something that was lost—not building from scratch the one thing that is elemental for any city's success.

In the absence of such a breakthrough, spending more money—or bragging about billions already spent—to continue tolerating intolerable conditions is nothing but an embarrassment.

Nicole Gelinas is a contributing editor to the Manhattan Institute's City Journal.