IN terms of intellect, Ben S. Bernanke may be to the Federal Reserve what John G. Roberts Jr. is to the Supreme Court. And like Chief Justice Roberts, Mr. Bernanke, the nominee to replace Alan Greenspan at the Fed, has left a paper trail worth studying. What can it tell us about the sort of Fed chairman he would be?

In general, Mr. Bernanke's work has been solidly in the mainstream - a mainstream he has helped define since he began publishing papers in major economic journals since 1981. He has written repeatedly about ways of using mathematical models of a dauntingly complex economy to set monetary policy. When he has strayed from that subject, his conclusions have sometimes raised eyebrows.

For example, in 2001 he joined Refet S. Gurkaynak of Bilkent University in Ankara, Turkey, in urging colleagues to adopt the sort of savings-driven models of the economy that the White House used to justify its tax cuts. David H. Romer, a professor of economics at the University of California, Berkeley, whose earlier work was discussed in the paper, said the statistical support for their argument was unconvincing.

In 1999, Mr. Bernanke and Mark Gertler, chairman of the economics department at New York University, wrote that financially fragile countries should not adopt fixed exchange rates, because they had been associated with crises in the past - a logic that other economists have disputed.

"Most of my American colleagues seem to go in this direction, but it's not a widely shared view around the world, and especially not in developing countries," said Charles Wyplosz, a professor of economics at the University of Geneva's Graduate Institute of International Studies. "The experience with floating interest rates is that they tend to float too much, so some sort of harnessing of the exchange-rate movements is useful for small, open economies."

These topics, however, are not at the core of what Mr. Bernanke would be concerned with at the Fed. There, his opinions about domestic monetary policy would be more important. One tenet of Mr. Bernanke's philosophy could not be clearer: that the central bank should use a model, not just hunches, to decide about interest rates and the money supply.

This is how he put it in 1997 in a paper with Michael Woodford, now a professor of political economy at Columbia: "We conclude that, although private-sector forecasts may contain information useful to the central bank, ultimately the monetary authorities must rely on an explicit structural model of the economy to guide their policy decisions."

Mr. Bernanke has examined exactly what data a central bank should use to calibrate its models. In 2003, he and Jean Boivin, an associate professor at the Columbia Business School, wrote that there was little advantage in waiting for "final" figures for government statistics, and that preliminary figures worked just as well for economic forecasts. The types of data used by the Fed could also change, said Anil K. Kashyap, a professor of economics and finance at the University of Chicago's business school.

"Greenspan was famous for looking at all these strange things like boxcar shipments," Professor Kashyap said, adding that Mr. Bernanke might prefer "indicators motivated by theoretical considerations," like banks' loan commitments.

Yet even in the "data-rich environment" that Mr. Bernanke and Professor Boivin described, models don't always encompass every possible outcome. Though models can explain various facets of the economy's behavior, even several at a time, no one has come up with a single formula that explains virtually everything.

To wit: a recent theme of Mr. Bernanke's work, one that he expounded as a Fed governor, is that the central bank should not try to prick bubbles in asset prices - mostly because it's too hard to tell when a bubble is really present. In that 1999 paper, he and Professor Gertler supplied a model to show how monetary policy should react to changes in asset prices.

Rudiger Dornbusch, the late professor of economics at the Massachusetts Institute of Technology, said the model lacked one important feature. "When it comes to monetary policy and asset price volatility," he wrote, "the interesting issue is not the gentle part of the trip but rather when it crashes." At that point, credit and liquidity can dry up.

"Neither of these considerations has a place in the Bernanke-Gertler model, which is just price-based and lacks rationing and liquidity," Professor Dornbusch concluded. The absence of liquidity and the onset of credit rationing, he argued, can be extremely important factors in forming policy at times of crisis.

Interestingly, Mr. Bernanke and Professor Gertler wrote a few years earlier that monetary policy might be most powerful during periods of tight credit, because of its effects on banks' balance sheets. But the periods of tightest credit - usually just before, during and after a crash in the markets - are the ones that are most difficult to model.

That is not to say that Mr. Bernanke would shy away from radical action in a crash. In an early version of a paper with Professor Gertler that was eventually published in 1990, they wrote that "under some circumstance, government 'bailouts' of insolvent debtors may be a reasonable alternative in periods of extreme financial fragility."

PROFESSOR ROMER at Berkeley said he believed that Mr. Bernanke would know when to discard his models. "He of course understands that even in normal times, the best model is just a guide," Professor Romer said. "If something extraordinary happens, like either Russia goes under or the stock market goes down by 20 percent, anyone with a modicum of common sense knows that the model's not going to be a reliable guide."

Despite their differences, Professor Romer gave Mr. Bernanke high marks as a potential Fed chairman. The professor's view carries some weight; in 2004, he and his wife, Christina D. Romer, also a professor of economics at Berkeley, published a paper entitled "Choosing the Federal Reserve Chair: Lessons From History."

"It's not your political abilities or who you know," David Romer said. "What does matter is your understanding of the economy and the effects of monetary policy. By that standard, Ben is the best person you could choose, basically."

The Federal Reserve is expected to raise interest rates on Tuesday and signal further increases, after recent speeches by Fed policymakers highlighting concerns about inflation risks.

While there has been no indication that the Federal Open Market Committee will change its judgment that monetary policy remains "accommodative" and that it will continue to raise rates at a "measured" pace, there is a widespread feeling that part of the statement will need to change soon.

A decision on Tuesday to raise rates to 4 per cent which would be the 12th consecutive quarter-point rate increase is unlikely to provoke controversy. Mark Olson, the Fed governor who voted against September's increase, is likely to fall back into line, given good recent data.

One concern is that the federal funds rate is no longer obviously well below the so-called "neutral" level, at which monetary policy neither restricts nor stimulates activity. But there does not yet appear to be a consensus on what should happen next, and the current language in the Fed's statement is seen as acceptable for now, with the FOMC likely to raise rates again in December.

Estimates of the neutral rate tend to put it in a range centred on 4.25 per cent. Fed policymakers rarely discuss such numbers but Janet Yellen, president of the San Francisco Fed, recently estimated the neutral rate from 3.5 to 5.5 per cent. "The current federal funds rate is toward the lower end of this band," she said in a speech.

The economy continued to grow at a healthy 3.8 per cent rate in the third quarter, according to the Commerce Department's advance estimate, providing further evidence to support the Fed's view that there is good momentum in spite of high energy prices. The economy's long-term potential rate is often put at 3.25 to 3.5 per cent. There has been no sign that the economy was knocked off course by the hurricanes, though high natural gas prices remain a concern.

The Fed's focus on inflation reflects in part the fact that the rise in energy prices is expected to feed into higher core inflation.

The Fed's favoured measure of core inflation is already at the top of the 1-2 per cent "comfort" range popularised by Ben Bernanke, the former Fed governor nominated last week to replace Alan Greenspan at the helm.

The FOMC will react to the incoming inflation and growth data. Key questions include inflation expectations and the extent of cost pressures from the labour market. High energy prices are a risk for both inflation and growth. With housing prices expected to level off at some point, a major uncertainty is whether business investment will pick up to take the strain if consumer spending slows.

TOKYO, Oct. 17 - Prime Minister Junichiro Koizumi's visit to a nationalist war memorial here drew immediate and fierce criticism from Asian countries today, threatening to isolate Japan in the region and deepen its already strained relations with China.

Beijing condemned the visit to the memorial, the Yasukuni shrine, as "a serious provocation to the Chinese people," and canceled bilateral talks on the North Korean nuclear crisis scheduled for today. South Korea also announced that it would cancel or postpone a trip to Japan scheduled for December by President Roh Moo Hyun, citing the shrine visit.

After months of speculation about the timing of this year's visit, Mr. Koizumi this morning fulfilled his promise of praying annually at the memorial. The Shinto shrine, which deifies Japan's 2.5 million war dead, including Class A war criminals responsible for atrocities throughout Asia, is regarded by most Asians as the symbol of unrepentant Japanese militarism.

"Prime Minister Koizumi has to bear the historic responsibility for damaging China-Japan relations," China's ambassador to Japan, Wang Yi, said in a statement.

In Seoul, a presidential spokesman, Kim Man-Soo, said that the South Korean government was no longer planning for a summit meeting in December or one-to-one talks between the two leaders at next month's Asia-Pacific Economic Cooperation meeting in Pusan, South Korea.

At a tense summit meeting in Seoul last June, President Roh told Mr. Koizumi that the visits to Yasukuni lay at the "core" of problems between the two nations. Until early this year, relations between Japan and South Korea had improved to such an extent that two summit meetings had been planned annually, one in each country.

The visit also drew protests from Taiwan and Singapore, two other nations that suffered under Japanese militarism. The leaders of the Yasukuni shrine and its museum have long stood at the center of a movement to justify Japan's prewar conduct. Their argument is that Japan tried to liberate Asia from Western powers and was pushed into World War II by the United States, and that war criminals enshrined there were innocent.

As Mr. Koizumi has led Japan to adopt a more assertive foreign policy, more and more politicians and public figures have also been openly trying to justify Japan's past. Their message has resonated in a country where anxieties over a shrinking population, uncertain economic prospects and China's rise in power have led to an increase in nationalist sentiments.

Mr. Koizumi rejected criticism of his visit, saying that he was merely paying homage to Japan's war dead.

"From a long-term perspective, I believe China will understand," Mr. Koizumi said. "No foreign government should criticize the way we mourn our war dead."

Mr. Koizumi, who arrived at the shrine in his official car, was flanked by a phalanx of bodyguards, and was seen praying in live broadcasts across the nation. He said he visited the shrine as a private citizen.

To downplay his visit's significance, Mr. Koizumi wore a gray suit, in contrast to the formal wear of his previous visits. He also refrained from entering the inner shrine and did not follow the precise Shinto ritual of bowing and clapping.

"It is extremely regrettable that the prime minister offered prayers at Yasukuni shrine where Class A war criminals are enshrined," said the leader of the main opposition Democratic Party, Seiji Maehara. "I think he should surely be aware that the prime minister, as a public official, cannot distinguish the official from the private."

Mr. Koizumi's muted visit, though, appeared to be a concession to growing criticism at home, with most polls showing the public opposed to his continued visits.

Takenori Kanzaki, the leader of the New Komeito Party, the governing party's junior coalition partner, told reporters that Mr. Koizumi probably took into consideration a ruling last month by the Osaka High Court that his visits violated Japan's constitutional separation of religion and the state.

It was perhaps also a slight concession to Japanese business leaders, who have openly criticized his visits and had dreaded any future ones. While Japan's political leadership has tended to regard an increasingly powerful China as a threat, its business leaders see it as an opportunity. Indeed, the Japanese economy has revived recently thanks in great part to China.

Hiroshi Okuda, the chairman of Toyota and of Nippon Keidanren, Japan's powerful business association, said in a statement that the prime minister had given consideration to domestic and international affairs by visiting the shrine as a private person. Both organizations strongly supported Mr. Koizumi in last month's general election.

But Kakutaro Kitashiro, the chairman of the Japan Association of Corporate Executives, another powerful association which supported Mr. Koizumi last month, was more critical.

"His visit has drawn criticism from our neighboring countries," Mr. Kitashiro said in a statement. "So we hope that he will fully recognize that it might damage our national interest, that careful explanations must be given to our neighboring countries and that diplomatic efforts must be made to gain their understanding."

NEW ORLEANS, Sept. 25 - After the storm came the siege. In the days after Hurricane Katrina, terror from crimes seen and unseen, real and rumored, gripped New Orleans. The fears changed troop deployments, delayed medical evacuations, drove police officers to quit, grounded helicopters. Edwin P. Compass III, the police superintendent, said that tourists - the core of the city's economy - were being robbed and raped on streets that had slid into anarchy.

The mass misery in the city's two unlit and uncooled primary shelters, the convention center and the Superdome, was compounded, officials said, by gangs that were raping women and children.

A month later, a review of the available evidence now shows that some, though not all, of the most alarming stories that coursed through the city appear to be little more than figments of frightened imaginations, the product of chaotic circumstances that included no reliable communications, and perhaps the residue of the longstanding raw relations between some police officers and members of the public.

Beyond doubt, the sense of menace had been ignited by genuine disorder and violence that week. Looting began at the moment the storm passed over New Orleans, and it ranged from base thievery to foraging for the necessities of life.

Police officers said shots were fired for at least two nights at a police station on the edge of the French Quarter. The manager of a hotel on Bourbon Street said he saw people running through the streets with guns. At least one person was killed by a gunshot at the convention center, and a second at the Superdome. A police officer was shot in Algiers during a confrontation with a looter.

It is still impossible to say if the city experienced a wave of murder because autopsies have been performed on slightly more than 10 percent of the 885 dead.

[On Wednesday, however, Dr. Louis Cataldie, the state's medical incident commander for Hurricane Katrina victims, said that only six or seven deaths appear to have been the result of homicides. He also said that people returning to homes in the damaged region have begun finding the bodies of relatives.

[Superintendent Compass, one of the few seemingly authoritative sources during the days after the storm, resigned Tuesday for reasons that remain unclear. His departure came just as he was coming under criticism from The New Orleans Times-Picayune, which had questioned many of his public accounts of extreme violence.]

In an interview last week with The New York Times, Superintendent Compass said that some of his most shocking statements turned out to be untrue. Asked about reports of rapes and murders, he said: "We have no official reports to document any murder. Not one official report of rape or sexual assault."

On Sept. 4, however, he was quoted in The Times about conditions at the convention center, saying: "The tourists are walking around there, and as soon as these individuals see them, they're being preyed upon. They are beating, they are raping them in the streets."

Those comments, Superintendent Compass now says, were based on secondhand reports. The tourists "were walking with their suitcases, and they would have their clothes and things taken," he said last week. "No rapes that we can quantify."

Rumors Affected Response

A full chronicle of the week's crimes, actual and reported, may never be possible because so many basic functions of government ceased early in the week, including most public safety record-keeping. The city's 911 operators left their phones when water began to rise around their building.

To assemble a picture of crime, both real and perceived, The New York Times interviewed dozens of evacuees in four cities, police officers, medical workers and city officials. Though many provided concrete, firsthand accounts, others passed along secondhand information or rumor that after multiple tellings had ossified into what became accepted as fact.

What became clear is that the rumor of crime, as much as the reality of the public disorder, often played a powerful role in the emergency response. A team of paramedics was barred from entering Slidell, across Lake Pontchartrain from New Orleans, for nearly 10 hours based on a state trooper's report that a mob of armed, marauding people had commandeered boats. It turned out to be two men escaping from their flooded streets, said Farol Champlin, a paramedic with the Acadian Ambulance Company.

On another occasion, the company's ambulances were locked down after word came that a firehouse in Covington had been looted by armed robbers of all its water - a report that proved totally untrue, said Aaron Labatt, another paramedic.

A contingent of National Guard troops was sent to rescue a St. Bernard Parish deputy sheriff who radioed for help, saying he was pinned down by a sniper. Accompanied by a SWAT team, the troops surrounded the area. The shots turned out to be the relief valve on a gas tank that popped open every few minutes, said Maj. Gen. Ron Mason of the 35th Infantry Division of the Kansas National Guard.

"It's part of human nature," General Mason said. "When you get one or two reports, it echoes around the community."

Faced with reports that 400 to 500 armed looters were advancing on the town of Westwego, two police officers quit on the spot. The looters never appeared, said the Westwego police chief, Dwayne Munch.

"Rumors could tear down an entire army," Chief Munch said.

During six days when the Superdome was used as a shelter, the head of the New Orleans Police Department's sex crimes unit, Lt. David Benelli, said he and his officers lived inside the dome and ran down every rumor of rape or atrocity. In the end, they made two arrests for attempted sexual assault, and concluded that the other attacks had not happened.

"I think it was urban myth," said Lieutenant Benelli, who also heads the police union. "Any time you put 25,000 people under one roof, with no running water, no electricity and no information, stories get told."

Crimes of Opportunity

The actual, serious crime began, in the recollection of many, before the catastrophic failure of the levees flooded the city, and much of it consisted of crimes of opportunity rather than assault. On the morning of Monday, Aug. 29, in the half hour or so that the eye of Hurricane Katrina fell on the city - an illusory moment of drawn breath, sunshine and fair breezes - the looters struck, said Capt. Anthony W. Canatella, the police commander in the Sixth District.

Using a chain hitched to a car, they tore open the steel doors at the back of a pawn shop called Cash America on Claiborne Avenue. "Payday Advances to 350," read a sign where the marquee would have been.

"There was nothing in there you could sustain your life with," Captain Canatella said. "There's nothing in there but guns and power tools."

The Sixth District - like most of New Orleans, a checkerboard of wealth and poverty - was the scene of heavy looting, with much of the stealing confined to the lower-income neighborhoods. A particular target was a Wal-Mart store on Tchoupitoulas Street, bordering the city's elegant Garden District and built on the site of a housing project that had been torn down.

The looters told a reporter from The Times that they followed police officers into the store after they broke it open, and police commanders said their officers had been given permission to take what they needed from the store to survive. A reporter from The Times-Picayune said he saw police officers grabbing DVD's.

A frenzy of stealing began, and the fruits of it could be seen last week in three containers parked outside the Sixth District police station. Inside were goods recovered from stashes placed by looters in homes throughout the neighborhood, said Captain Canatella, most but not all still bearing Wal-Mart stickers.

"Not one piece of educational material was taken - the best-selling books are all sitting right where they were left," Captain Canatella said. "But every $9 watch in the store is gone."

One of the officers who went to the Wal-Mart said the police did not try to stop people from taking food and water. "People sitting outside the Wal-Mart with groceries waiting for a ride, I just let them sit there," said Sgt. Dan Anderson of the Sixth District. "If they had electronics, I just threw it back in there."

Three auto parts stores were also looted. In a house on Clara Street, Sergeant Anderson picked his way through a soggy living room, where car parts, still in their boxes, were strewn about. On the wall above a couch, someone had written "Looters" with spray paint.

"The nation's realizing what kind of criminals we have here," Sergeant Anderson said.

Among the evacuees, there was gratitude for efforts by the police and others to help them get out of town, but it was clear that some members of the public did not have a high opinion of the New Orleans Police Department, with numerous people citing cases of corruption and violence a decade ago.

"Don't get me wrong, there was bad stuff going on in the streets, but the police is dirty," said Michael Young, who had worked as a waiter in the Riverwalk development.

French Quarter Is Spared

As the storm winds died down that Monday, small groups that had evacuated from poor neighborhoods as far away as the Lower Ninth Ward passed through the historic French Quarter, heading for shelter at the convention center.

"Some were pushing little carts with their belongings and holding onto their kids," said Capt. Kevin B. Anderson, the French Quarter's police commander. He said his officers gave food, water and rides. "That also served another purpose," he said. "That when they came through, they didn't cause any problems."

The jewelry and antique shops in the French Quarter were basically left untouched, though squatters moved into a few of the hotels. Only a small grocery store and drugstores at the edge of the quarter were hit by looters, he said. From behind the locked doors of the Royal Sonesta hotel on Bourbon Street, Hans Wandfluh, the general manager, said he had watched passers-by who seemed to be up to no good. "We heard gunshots fired," Mr. Wandfluh said. "We saw people running with guns."

At dusk on Aug. 29, looters broke windows along Canal Street and swarmed into drugstores, shoe stores and electronics shops, Captain Anderson said. Some tried, without success, to break into banks, and others sought to take money from A.T.M.'s.

The convention center, without water, air-conditioning, light or any authority figures, was recalled by many as a place of great suffering. Many heard rumors of crime, and saw sinister behavior, but few had firsthand knowledge of violence, which they often said they believed had taken place in another part of the half-mile-long center.

"I saw Coke machines being torn up - each and every one of them was busted on the second floor," said Percy McCormick, a security guard who spent four nights in the convention center and was interviewed in Austin, Tex.

Capt. Jeffrey Winn, the commander of the SWAT team, said its members rushed into the convention center to chase muzzle flashes from weapons to root out groups of men who had taken over some of the halls. No guns were recovered.

State officials have said that 10 people died at the Superdome and 24 died around the convention center - 4 inside and 20 nearby. While autopsies have not been completed, so far only one person appears to have died from gunshot wounds at each facility.

In another incident, Captain Winn and Lt. Dwayne Scheuermann, the assistant SWAT commander, said they both shot and wounded a man brandishing a gun near people who had taken refuge on an Interstate highway. Captain Winn said the SWAT team also exchanged gunfire with looters on Tchoupitoulas Street.

The violence that seemed hardest to explain were the reports of shots being fired at rescue and repair workers, including police officers and firefighters, construction and utility workers.

Cellphone repair workers had to abandon work after shots from the Fischer housing project in Algiers, Captain Winn said. His team swept the area three times. On one sweep, federal agents found an AK-47 semiautomatic rifle, Captain Winn said.

For military officials, who flew rescue missions around the city, the reports that people were shooting at helicopters turned out to be mistaken. "We investigated one incident and it turned out to have been shooting on the ground, not at the helicopter," said Maj. Mike Young of the Air Force.- Nathan Levy contributed reporting from Austin, Tex., for this article.

Filed at 1:22 a.m. ET

Text of the joint statement issued Monday by six nations at talks in Beijing on North Korea's nuclear program:

For the cause of peace and stability on the Korean Peninsula and in northeast Asia at large, the six parties held in a spirit of mutual respect and equality serious and practical talks concerning the denuclearization of the Korean Peninsula on the basis of the common understanding of the previous three rounds of talks and agreed in this context to the following:

1) The six parties unanimously reaffirmed that the goal of the six-party talks is the verifiable denuclearization of the Korean Peninsula in a peaceful manner.

The Democratic People's Republic of Korea (North Korea) committed to abandoning all nuclear weapons and existing nuclear programs and returning at an early date to the treaty on the nonproliferation of nuclear weapons (NPT) and to IAEA (International Atomic Energy Agency) safeguards.

The United States affirmed that is has no nuclear weapons on the Korean Peninsula and has no intention to attack or invade the DPRK with nuclear or conventional weapons.

The ROK (South Korea) reaffirmed its commitment not to receive or deploy nuclear weapons in accordance with the 1992 joint declaration of the Denuclearization of the Korean Peninsula, while affirming that there exist no nuclear weapons within its territory.

The 1992 joint declaration of the Denuclearization of the Korean Peninsula should be observed and implemented.

The DPRK stated that it has the right to peaceful uses of nuclear energy.

The other parties expressed their respect and agreed to discuss at an appropriate time the subject of the provision of light-water reactor to the DPRK.

2) The six parties undertook, in their relations, to abide by the purposes and principles of the Charter of the United Nations and recognized norms of international relations.

The DPRK and the United States undertook to respect each other's sovereignty, exist peacefully together and take steps to normalize their relations subject to their respective bilateral policies.

The DPRK and Japan undertook to take steps to normalize their relations in accordance with the (2002) Pyongyang Declaration, on the basis of the settlement of unfortunate past and the outstanding issues of concern.

3) The six parties undertook to promote economic cooperation in the fields of energy, trade and investment, bilaterally and/or multilaterally.

China, Japan, the Republic of Korea (ROK), Russia and the U.S. stated their willingness to provide energy assistance to the DPRK. The ROK reaffirmed its proposal of July 12, 2005, concerning the provision of 2 million kilowatts of electric power to the DPRK.

4) Committed to joint efforts for lasting peace and stability in northeast Asia. The directly related parties will negotiate a permanent peace regime on the Korean Peninsula at an appropriate separate forum.

The six parties agreed to explore ways and means for promoting security cooperation in northeast Asia.

5) The six parties agreed to take coordinated steps to implement the aforementioned consensus in a phased manner in line with the principle of ''commitment for commitment, action for action.''

6) The six parties agreed to hold the fifth round of the six party talks in Beijing in early November 2005 at a date to be determined through consultations.

BEIJING, Sept. 19 - North Korea agreed to end its nuclear weapons program this morning in return for security, economic and energy benefits, potentially easing tensions with the United States after a three-year standoff over the country's efforts to build atomic bombs.

The United States, North Korea and four other nations participating in nuclear negotiations in Beijing signed a draft accord in which Pyongyang promised to abandon efforts to produce nuclear weapons and re-admit international inspectors to its nuclear facilities. Foreign powers said they would provide aid, diplomatic assurances and security guarantees and consider North Korea's demands for a light-water nuclear reactor.

The agreement is a preliminary one that would require future rounds of negotiations to flesh out, as it does not address a number of issues, like timing and implementation, that are likely to prove highly contentious. China announced that the six nations participating in the talks would reconvene in November to continue ironing out the details.

Even so, the agreement marks the first time since the United States accused North Korea of violating a previous accord in 2002 that the two countries have drawn up a road map for ending their dispute through peaceful means.

It also appears to rescue a diplomatic process that appeared to be on the verge of collapse after multiple rounds of negotiations failed to produce even a joint statement of principles. The Bush administration had said it was prepared to take tougher measures, including freezing North Korean assets abroad and pushing for international sanctions, if the latest round of talks collapsed.

"The problem is not yet solved but we hope it can be solved eventually through this agreement," said Christopher Hill, the chief American negotiator. "We have to take the momentum of this agreement and see that it is implemented."

Mr. Hill said that negotiations with the North Koreans were torturous at every stage and that he expects that the broad agreement will take time to put into practice. But he called the signing a "turning point."

"This is first time they have committed to completely dismantle their weapons in an international agreement," Mr. Hill said. "They cannot just stall and pretend it does not exist. I think they have gotten the message."

Mr. Hill said he was willing in principle to travel to Pyongyang in the near future to continue discussions, though he said any such trip would require approval from the Bush administration.

In Washington, President Bush reacted cautiously this morning, calling the North Korean move "a positive step."

"It was a step forward in making this word a more secure place," Mr. Bush said. "The question is, over time, will all parties adhere to the agreement."

Progress in the North Korean talks could give the United States and European countries some diplomatic momentum in their negotiations with Iran over that country's nuclear weapons program, which is not considered as advanced as the North Korean one.

More generally, it would appear to increase support for people inside the Bush administration who favored pursuing laborious negotiations with the North Koreans. Hardliners in the administration and in Congress had raised questions about the usefulness of negotiations with the country, which they have argued has no intention of abandoning its nuclear weapons.

Critics of the agreement will likely point to the fact that it remains vague on the sequence of concessions that North Korea, the United States and other parties agreed to make, meaning that negotiation could drag on for many more months before any progress is made in slowing the North's program to develop nuclear weapons.

"It is significant that the countries have agreed on a broad set of principles," said Koh Yu Hwan, a North Korea expert at Dong Guk University in Seoul. "But they postponed addressing the hot-potato issues to prevent the talks from collapsing."

Most pointedly, the agreement finesses the North Korean demand that proved the biggest stumbling block in the latest round of talks - its condition that the outside world provide a light-water nuclear reactor that it says it will use to produce electricity. The issue is left essentially unresolved, potentially leaving both sides to claim that their views prevailed.

The agreement states that the United States, China, Russia, Japan and South Korea will discuss providing North Korea with a light-water reactor "at the appropriate time." Appropriate is not defined in the text, leaving open the possibility that North Korea will continue to insist on receiving that concession as a first step before it gives up its nuclear weapons.

A senior American official said all the other parties made clear to North Korea that "the appropriate time" would come only after North Korea rejoined the Nuclear Nonproliferation Treaty and re-admitted nuclear inspectors. He added that North Korea would not be able to achieve those goals until it dismantles its nuclear program.

But the official acknowledged that the issue had proven to be the most sensitive one for the Bush administration. After the Chinese side introduced a compromise draft agreement on Friday, it took the administration the full weekend to decide whether it could accept the mention of the light-water reactor, the official said. He asked not to be identified in discussing the thinking of other administration officials.

One reason it proved sensitive is that it echoes a 1994 accord to end North Korea's nuclear program that had been negotiated by the Clinton administration. That accord, known as the "agreed framework," called for the construction of two light-water nuclear reactors in North Korea in return for the North freezing and later ending its weapons program.

The Bush administration criticized the concessions the Clinton administration made to achieve that agreement and later accused North Korea of violating it, which led to the standoff.

The administration official emphasized that the new accord does not repeat what he viewed as the main mistake of the agreed framework because it does not focus on "freezing" the North's nuclear program, but makes its total abandonment the benchmark for progress.

"We were very careful not to get caught up in the notion of a freeze," he said. Although many details remain unresolved, the accord appears to be a significant victory for China. Beijing cajoled both the United States and North Korea to continue meeting each other despite repeated threats by both sides to discontinue negotiations.

In the latest round of talks, Beijing brokered the compromise agreement after four days of discussions left the talks in a deadlock. It then insisted that the text had to remain unchanged, forcing the parties to get approval for the agreement from their capitals. It took several days and some intensive bargaining sessions to line up support, but the Chinese draft was agreed to with only small alternations, participants in the talks said.

"I think they found the red line for the North Koreans and then stuck with that text," said the American official.

China has long argued that North Korea's nuclear problems cannot be dealt with through pressure or military force and must be addressed through comprehensive negotiations aimed at addressing Pyongyang's full range of concerns.

The Bush administration also overhauled the substance and the style of its approach to North Korea. Officials stopped using the accusatory language President Bush once used when he called North Korea a member of the "axis of evil" and called the nation's leader, Kim Jong-Il, a tyrant.

Instead, the Americans have worked closely with South Korea and China to address North Korea's security and economic concerns and reassured Pyongyang that it recognizes the country as sovereign. Officials relaxed their stand on the North retaining some kind of peaceful nuclear program.

The new agreement commits North Korea to scrap all of its existing nuclear weapons and nuclear production facilities, to rejoin the Nuclear Non-Proliferation Treaty, and to re-admit international nuclear inspectors. North Korea withdrew from the treaty and expelled inspectors in 2002.

The United States and North Korea also pledged to respect each other's sovereignty and right to peaceful co-existence and to work toward normalization of relations. The two countries do not have full diplomatic relations and did not sign a peace treaty after the Korean War.

Washington declared as part of the agreement that it does not now have any nuclear weapons at its bases in South Korea and that it "has no intention to attack or invade the DPRK with nuclear or conventional weapons."

The DPRK stands for the Democratic People's Republic of Korea, North Korea's formal name.

On the question of civilian uses of nuclear power, today's agreement states that North Korea claims the right to pursue "peaceful uses of nuclear energy." It went on to say, "The other parties expressed their respect and agreed to discuss at an appropriate time the subject of the provision of light-water reactor to the DPRK."

Mr. Hill said he expected that a light-water reactor would cost $2 billion to $3 billion and would take a decade to build. While a light-water reactor does not produce fuel for atomic weapons as efficiently as the North's existing modified-graphite reactors do, American officials have said that it still raises proliferation risks and cannot be a first step in arranging the nuclear disarmament of the country.

North Korea has said it requires the new nuclear plant to provide electricity. But Mr. Hill said building a new nuclear plant would be an inefficient way of boosting its electricity supplies. He said the North considers a civilian nuclear plant a "trophy."

The agreement includes a commitment by South Korea to build power plants and transmission lines to provide the North with 2,000 megawatts of electricity, enough to roughly double to total supply of electrical power for its northern neighbor.

NEW ORLEANS, Sept. 15 - President Bush called Thursday night for the rebuilding of the devastated Gulf Coast through the creation of a Gulf Opportunity Zone, a government enterprise that he said would provide help on taxes, housing, education and job training for the victims of Hurricane Katrina.

"The work that has begun in the Gulf Coast region will be one of the largest reconstruction efforts the world has ever seen," Mr. Bush said in remarks delivered in Jackson Square against the brightly lighted backdrop of St. Louis Cathedral, a symbol of the heart and soul of New Orleans for almost three centuries.

Mr. Bush delivered his speech, carried live by the major television networks, in the middle of the city's darkened French Quarter, where Army troops from the 82nd Airborne Division were on patrol. The Bush White House, well practiced in the art of presidential stagecraft, provided its own generators for the lighting and communications equipment that beamed Mr. Bush's remarks to the nation.

"And tonight I also offer this pledge of the American people: Throughout the area hit by the hurricane, we will do what it takes, we will stay as long as it takes to help citizens rebuild their communities and their lives," Mr. Bush said.

The mayor of New Orleans announced Thursday that residents and business owners could return to some parts of the city during daylight.

Mr. Bush ordered an immediate review of emergency plans for all cities, and said there was a need for greater federal authority and a broader role for armed forces in certain emergencies. He called for a federal government assessment of his administration's response to the storm and said that he would work with both parties in Congress in an investigation of what went wrong.

"This government will learn the lessons of Hurricane Katrina," Mr. Bush said.

The president did not, however, embrace calls for an independent commission to investigate the disaster.

White House officials viewed the speech as the culmination of a pivotal week in which Mr. Bush tried to turn around his image as a chief executive slow to respond to the greatest natural disaster in American history. The speech was meant to portray Mr. Bush as a forceful leader in control of the crisis and sympathetic to the people in the region.

"Tonight, so many victims of the hurricane and flood are far from home and friends and familiar things," Mr. Bush said. "You need to know that our whole nation cares about you, and in the journey ahead you are not alone. To all who carry a burden, I extend the deepest sympathy of our country."

Mr. Bush, dressed uncharacteristically in shirt-sleeves for a formal national address, said that the Gulf Opportunity Zone, encompassing Louisiana, Mississippi and Alabama, would provide tax incentives and loans for small businesses, including, he pointed out, minority-owned enterprises. Mr. Bush also said the federal government would provide evacuees with accounts of up to $5,000 that they could use for job training and education.

In addition, he asked Congress to pass what he called an Urban Homesteading Act, which would provide building sites on federal land through a lottery to low-income citizens, free of charge. In return, Mr. Bush said, residents would promise to build on the lots, with either a mortgage or help from a charitable organization like Habitat for Humanity.

Mr. Bush spoke after he was driven through empty, pitch-black streets, where members of the 82nd Airborne stood on corners in the darkness saluting the motorcade.

"I am speaking to you from the city of New Orleans, nearly empty, still partly under water and waiting for life and hope to return," Mr. Bush said from a lectern set up in the grass and hidden behind camouflage netting in Jackson Square.

In the aftermath of the storm, Mr. Bush said, "we have seen fellow citizens left stunned and uprooted searching for loved ones, and grieving for the dead and looking for meaning in a tragedy that seems so blind and random."

In his fourth trip to the region since the storm, Mr. Bush directly addressed the suffering of the largely poor, black evacuees at the New Orleans Superdome and convention center: "We have also witnessed the kind of desperation no citizen of this great and generous nation should ever have to know - fellow Americans calling out for food and water, vulnerable people left at the mercy of criminals who had no mercy and the bodies of the dead lying uncovered and untended in the street."

The president said state and local officials would have the primary role in planning for reconstruction, and in changing zoning laws and building codes. He listed many of the relief efforts now under way, including the registration of evacuees and retraining for workers.

Mr. Bush also tackled the tough issues of race and poverty that have been the source of enormous criticism and caused even Republicans to question the administration's commitment: "As all of us saw on television, there is also some deep, persistent poverty in this region as well. And that poverty has roots in a history of racial discrimination, which cut off generations from the opportunity of America. We have a duty to confront this poverty with bold action. So let us restore all that we have cherished from yesterday, and let us rise above the legacy of inequality."

Mr. Bush did not offer cost estimates for his proposals on Thursday night, but they were drawn from the kind of experiments - with "opportunity zones" and tax incentives - that Republicans have greatly preferred to huge federal spending efforts. The president seemed to try to balance a comprehensive government plan with an assurance that Washington would back away and allow Louisiana, Mississippi and Alabama - and the city of New Orleans - to decide how to rebuild.

"That is our vision of the future, in this city and beyond: We will not just rebuild, we will build higher and better," he promised.

Aside from the opportunity zone, Mr. Bush also proposed "worker recovery accounts" of up to $5,000 that evacuees could use for job training and education. The proposal sounds much like the kinds of accounts set up after the passage of the North America Free Trade Agreement in the early 1990's to help retrain workers displaced by foreign competition, a program that met with mixed reviews.

But in his speech, Mr. Bush also left some of the most controversial ideas unmentioned. His words seemed to imply that New Orleans neighborhoods would be rebuilt on the same sites that were flooded, rather than letting that land return to its original state, as wetlands that could provide a relief valve in the case of a future flood. Many of the most vulnerable neighborhoods were largely occupied by the city's poorest, and relocating those neighborhoods opened issues that one White House official said today "are not for us to deal with."

"Protecting a city that sits lower than the water around it is not easy," Mr. Bush said, "but it can and has been done."

He added: "And all who question the future of the Crescent City need to know: There is no way to imagine America without New Orleans, and this great city will rise again."

The federal government, Mr. Bush said, will undertake a "close partnership" with Mississippi and Louisiana, with New Orleans and other Gulf Coast cities so they can rebuild in a "sensible, well-planned way." He said the federal government will cover the majority of the costs of rebuilding the infrastructure in the disaster zone, from roads and bridges to schools and water systems.

The president said he expected the work to be done quickly, and that taxpayers would expect it to be performed "honestly and wisely." He promised to have a team of inspectors reviewing all expenditures.

But many Republicans predicted that the costs could run as high or higher than the war in Iraq, up to $200 billion, and noted that the White House had said $51.8 billion in emergency federal funds just approved by Congress, on top of an earlier $10 billion, would last for just a few weeks. Mr. Bush did not name a lead rebuilding official in the speech, as some White House officials are urging, and Scott McClellan, the White House press secretary, did not rule out the naming of such an official at a later date. Gen. Tommy Franks, who commanded forces in Afghanistan and Iraq, and John F. Welch Jr., the former chief executive of General Electric, are names often mentioned by Republicans as possibilities.

The president's proposal for an opportunity zone draws on more than a decade of federal experience with offering tax credits and other incentives for investment in economically depressed areas.

In 2002, the Bush administration selected New Orleans as a renewal community, eligible to share in billions of dollars worth of federal tax incentives intended to stimulate job growth and economic development. Last October, Gov. Kathleen Babineaux Blanco of Louisiana said the program had helped create jobs and must expand across the Delta.

Mr. Bush's proposal goes further. He would provide tax breaks, loans and loan guarantees to encourage businesses to invest in areas hit by the hurricane.

The Government Accountability Office, an investigative arm of Congress, said last year that federal agencies did not collect the data needed to assess the existing program or to show how the tax benefits had been used.

The president's comments were met with praise from local officials, including Ms. Blanco, who along with other local officials listened to Mr. Bush's speech from a bench in Jackson Square.

"Louisiana's people are strong, optimistic and determined to rebuild this great region, but we cannot do it without the resources of our nation and our government," she said. "I take the president at his word when he says those resources will be there when we need them."

BEIJING, Sept. 16 - China proposed a new compromise solution to the North Korean nuclear standoff and gave participating countries one day to accept or reject the offer, but there were mixed signals today about whether the United States and North Korea were prepared to come to terms.

Beijing drew up a new agreement - its fifth such attempt in the latest round of talks - that diplomats said promised North Korea the right to retain a peaceful nuclear energy program and to receive a new light-water reactor at some point. The agreement also reflects American demands that any such steps occur after Pyongyang dismantles its nuclear weapons, the diplomats said.

The new draft prompted a flurry of excitement in Beijing after three-days of stalemate in the six-nation nuclear talks, but by late today it appeared uncertain whether North Korea and the United States had made much progress bridging their differences.

North Korea issued a strongly worded statement late in the day in which it insisted that it must receive a new light-water nuclear reactor before it abandons its nuclear weapons program, a sequence the United States has repeatedly dismissed as unacceptable.

"The U.S. is demanding that we give up our nuclear deterrent facilities first. I think this is such a naïve request," the North Korea spokesman, Hyun Hak Bong, said, reading a prepared text. "Our response is: Don't even dream about it."

Mr. Hyun said North Korea requires nuclear weapons because it has to defend itself against the United States, which he said has targeted his country for a "pre-emptive strike."

Earlier in the day, after a series of meetings with the North Koreans and the Chinese, the chief American negotiator, Christopher Hill, sounded a more optimistic note. He suggested that China had pushed the North Koreans to soften their position. But he warned that the negotiations were so far inconclusive.

"At this point, I don't know where this will lead," Mr. Hill said. "We're still in business."

Mr. Hill declined to comment on the talks late today after he spent the evening on the phone with Washington.

Diplomats said that China, the host of the talks, which involve Japan, South Korea and Russia as well as North Korea and the United States, told all parties that they would have to vote up or down on a re-drafted communiqué that China circulated today.

The United States accused North Korea of violating a previous agreement to end its nuclear program in 2002. Talks have been under way since 2003 to reach a new agreement, but so far they have failed to achieve even a broad statement of principles.

The main sticking point in this round involves North Korea's demand for a light-water reactor, which it claims it needs to supply electricity. It has rejected a South Korean offer to distribute power across the border to North Korea instead, even though Seoul says this could double North Korea's electricity supplies in short order.

The North was promised a light-water reactor in a 1994 accord, now defunct. In the latest talks, it is demanding that it receive the reactor first, before dismantling its nuclear weapons

The United States has sent mixed signals about whether the North could get a new reactor at some point. But Washington has made clear that it could not do so before Pyongyang ends its nuclear program and readmits international inspectors.

The Russian delegate at the talks, Alexander Alexeyev, said the latest agreement has "compromise wording which could satisfy both sides" and held out hope that an accord could be reached Saturday.

It is unclear what will happen if this round of talks fails. Asian diplomats said the Chinese are eager to keep the talks alive, perhaps by declaring another recess and reconvening the negotiations in the near future. But the United States has said that the talks cannot go on indefinitely.