PRESIDENT BUSH'S pledge to "do what it takes" to help New Orleans and the rest of the Gulf Coast recover from the devastation of Hurricane Katrina is a welcome signal of federal resolve and engagement after a faltering start. So, too, are his acknowledgment of personal responsibility and his recognition of the government's "duty to confront" the "deep, persistent poverty" exposed by the storm.

But as the federal focus shifts from the immediacy of rescue to the long-term job of recovery and rebuilding, the challenge will be to respond not only with compassion and generosity but with wisdom. The wallet-opening instinct is natural and justified in this extraordinary circumstance, but with $62 billion already allocated and scores, if not hundreds, of billions more to come, it's imperative to ensure a more robust and responsible federal role than willy-nilly check-writing.

Along with the president's empathy for the plight of Katrina's victims, it would have been useful to hear him acknowledge the hard choices ahead and the need to make adjustments elsewhere in the federal budget to accommodate the extra spending. "It's going to cost whatever it's going to cost," as Mr. Bush said yesterday, is far too cavalier an approach at a time when the federal budget is already under great strain. Mr. Bush asserts that the government can afford to spend on the Katrina cleanup "and our other priorities," and that the budget shortfall can be addressed by "cutting unnecessary spending."

But the evidence that he has the will to do that, and the backbone to stand up against lawmakers' parochial greed, has been lacking. See, for example, the recent pork-stuffed transportation bill. Yesterday Mr. Bush ruled out any tax increases to pay for the reconstruction; if that includes refusing to rethink his insistence on making the tax cuts permanent, that is not surprising but nonetheless disappointing.

However the federal spending is paid for, the government must put in place a strong structure to oversee the effort. This is important not only to guard against fraud but to make certain that the money goes where it is most needed and is spent in a way that makes most sense, rather than where the loudest political clamor arises or where the administration's ideological predispositions dictate.

There are already some worrisome signs. Instead of creating trailer towns of Katrina evacuees, for example, why not expand the federal government's voucher program -- a program the administration has repeatedly tried to cut -- to take advantage of the large numbers of vacant rental units? There are serious questions about whether Mr. Bush's proposed Gulf Opportunity Zone, which would grant tax breaks for business investment in equipment and buildings in the affected areas, would merely subsidize investment that would have happened anyway or draw it from elsewhere.

With the federal government poised, as the president promised, to contribute "the great majority of the costs of repairing the public infrastructure in the disaster zone, from roads and bridges to schools and water systems," it's essential that those projects be reviewed before the money is spent. Cost-benefit analysis should not stop at the storm's edge. To spend federal funds to rebuild parts of New Orleans that will remain at a high risk of flooding may not make sense.

Mr. Bush spoke Thursday night about the need for better zoning laws and tougher building codes, but he also emphasized that state and local officials will retain "the primary role in planning for their own future." That is obviously correct. To make certain it's not wasted, however, the federal money they use must come with sensible strings attached.