North Korea, one of the world's poorest, most isolated countries, is a difficult place to employ the containment strategy the United States is now pursuing. The world has little left to withdraw or withhold, according to diplomats and specialists. What levers exist largely have been pulled already -- most recently when the Bush administration cut fuel shipments upon learning that North Korea has a program to create enriched uranium for nuclear weapons.

"Economically, there really isn't that much else that we can do to pressure North Korea," said Lee Chung Min, a North Korea expert at Yonsei University in Seoul.

For the Bush administration, simply intensifying economic and political pressure on the North involves enormous political obstacles. South Korea has embraced engagement and dialogue as the best way to address the reclusive country to its north. It appears committed to that course -- a fact underscored today as South Korea's president, Kim Dae Jung, rejected containment as a failed doctrine.

"Pressure and isolation have never been successful with communist countries," Kim told his cabinet, in remarks distributed by the presidential Blue House. "Cuba is one example."

Nonetheless, the Bush administration has concluded that the regional powers in Asia, especially China and Russia, must take a greater role in resolving the crisis over North Korea's nuclear ambitions, and it is urging those nations to exert maximum pressure on Pyongyang, U.S. officials said today. [Details, Page A14.]

Effective economic pressures will all but certainly need the backing of the U.N. Security Council, Lee said. But one council member, Russia, sells military equipment to North Korea and has been openly critical of the Bush administration's handling of the confrontation. "Attempts to isolate North Korea can only lead to a new escalation in tension," Russian Foreign Minister Igor Ivanov said today.

Another Security Council member, China, now provides North Korea with food and fuel, and appears unlikely to embrace the U.S. approach.

"Of course, China will not support containment," said Jin Linbuo, an Asian security expert at the government-affiliated China Institution of International Studies in Beijing. "If North Korea is in turmoil, then lots of refugees will crowd into China. Moreover, if North Korea collapses, then the Korean Peninsula would be wholly controlled by the United States and its coterie. North Korea's existence protects China from American military domination."

In one respect, the logic of containment rests on indisputably solid ground: North Korea is in dire straits, its economy vulnerable and its livelihood increasingly dependent on outside largess.

Beyond North Korea's capital, Pyongyang, people sometimes freeze to death in darkened, unheated homes because of a shortage of energy, according to defectors. Power stations are idled for lack of fuel, and factories run at about 30 percent of capacity, said Park Suhk Sam, a North Korea expert in the research arm of the Bank of Korea, South Korea's central bank. What energy is available is directed mostly toward the capital, and at factories that make weapons, say recent visitors.

According to Kim Tae Woo, an arms control expert at the Korea Institute for Defense Analyses in Seoul, North Korea's government secures about $580 million a year through the sale of missiles and missile technology to countries including Yemen, Syria, Egypt and Iran. In an economy whose annual output is estimated at $15.7 billion, those sales are a crucial source of hard currency. Stopping the trade is a requirement for making containment work, Kim said.

Roughly half of North Korea's energy supplies are derived from domestically mined coal, according to Oh Seung Ryeol, an economist at the Korea Institute for National Unification, a research group affiliated with the South Korean government. The other half comes from imports -- the bulk of it from China, as well as some from the Middle East. When the Bush administration halted fuel shipments, that lopped off another portion of North Korea's electricity supply, Oh said.

"Their ability to produce daily necessities is very limited," he said. "They are suffering from serious economic shortages."

Agriculture makes up nearly a third of North Korea's economic output. But the U.N. World Food Program estimated that half of North Korea's tractors are now idled because of a lack of spare parts, tires and gasoline. Oxen are increasingly being pressed into service to compensate for the shortage, an example of the backward steps for which the country is known.

Food is in critically short supply. Though the World Food Program concluded that this year's harvest was slightly better than last year's, North Korea still lacked more than 1 million tons of grain needed to satisfy minimum caloric needs for its 22 million people. According to Oh, North Korea typically produces about 80 percent of the food it needs while importing the rest, most of it from China.

Japan, South Korea and the United States have all made significant contributions of food to North Korea in recent years. But that aid is now in doubt. The World Food Program -- which coordinates aid shipments -- recently warned that it will not be able to feed nearly 3 million people in need, including 760,000 children in nurseries.

The United States has enunciated tough new rules for further food aid to the North. South Korea, which ships nearly $300 million in clothing and food to North Korea, would be deeply reluctant to follow suit.

"South Koreans look at the North and say, 'They are our brothers,' " said a Western diplomat.

Even if containment does make life more miserable for millions of North Koreans, it would not necessarily translate into sufficient pressure on the regime. North Korea's history has proved the endurance of the so-called Great Leader, Kim Jong Il, whose life of excess against the backdrop of broad suffering often draws comparisons to Romania's Nicolae Ceausescu.

In the mid-1990s, natural disasters and the loss of fertilizers and machinery from the Soviet Union led to a series of disastrous harvests and widespread famine in North Korea. While the government said about 200,000 people died, outside experts put the toll at 10 times that number. Many in the South predicted, wrongly, that Kim Jong Il would not endure.

"We cannot assess the stability of North Korea using a Western standard," said Kim Tae Woo, the defense analyst. The famine appears not to have dented Kim Jong Il's willingness to indulge. In a book published recently in Moscow, a Russian general who traveled with Kim last year aboard his personal rail car -- en route to Moscow to meet with President Vladimir Putin -- described orgies of food washed down by French wines. For one meal, they had fresh lobster.

"Every day on board we would discuss the menu for the next day," wrote the Russian general, Konstantin Pulikovsky. "Kim suggested doing so, saying that he had great cooks, who were educated in France. One could order any dish from Russian, Chinese, Korean, Japanese and French cuisine. Usually the menu he chose consisted of 15-20 dishes."

North Korea's dire economic conditions have, however, forced Kim to alter some policies. When the famine peaked, he reluctantly accepted aid shipments from his biggest enemies: the United States, Japan and South Korea. Since then, he has experimented with economic reforms reminiscent of China's market-opening moves of two decades ago, allowing some private enterprise to take root and foreign businesses to set up operations.

South Korean entrepreneurs have responded, shifting manufacturing to factories outside Pyongyang. Just north of the Demilitarized Zone that divides the Korean Peninsula, at a newly minted free trade zone called Kaesong, a South Korean entrepreneur is playing a central role in North Korea's grandest experiment with capitalism -- a $9 billion industrial park that will include thousands of factories, homes and hotel rooms. About 500,000 South Koreans have visited Mount Kumgang, a walled-off scenic area developed for tourism inside North Korea.

But even as this trend intensifies, trade between the Koreas amounted to a mere $400 million last year, according to Park, the Bank of Korea economist, so stopping it would not have significant consequences. Much of the trade would be difficult to stop anyway, because South Korean entrepreneurs -- anticipating such a move -- have routed much of their business through ports in other countries, principally in China, Park said.

In the 1980s and into the early 1990s, ethnic Koreans living in then-booming Japan sent as much as $1.5 billion a year back to relatives in the North and to Kim's family, according to Tsutomu Nishioka, an expert at the Modern Korea Institute in Tokyo. Much of the money was raised through real estate ventures and pachinko pinball parlors, then carried back in suitcases full of cash on a passenger boat -- the Mangyongbong -- that runs about twice a month between the northern Japanese port of Niigata and Wonsan, on North Korea's east coast.

The Mangyongbong also carried goods such as computers, machine tools and parts for high-quality Japanese tractors, which were needed to construct North Korea's underground military bunkers, Nishioka said.

But when Japan's good times ended, the flow of money turned to a trickle: Nishioka now estimates that no more than $160 million a year makes its way to North Korea from Japan's ethnic Koreans. At the same time, tightened export controls that followed North Korea's test-firing of a missile over Japan in 1998 have sharply limited the transport of technology on the Mangyongbong, though the boat does carry luxury items for Kim Jong Il, said Lee Yong Hwa, a North Korea expert at Kansai University in Osaka.

Ultimately, any effort that does not enjoy China's genuine backing is doomed to fail, experts say. China is not only North Korea's largest external source of food and fuel, but also its largest trading partner and its gateway to the rest of the world.

North Korean textiles are trucked into China, then shipped to Japan and sold with "Made in China" labels, Western diplomats said. China's long border with North Korea has become a kind of anything-goes frontier. According to visitors to the area, North Koreans bribe their way past Chinese border guards to enter nearby towns and cities. There they take jobs that even local Chinese do not want, at lower wages, laboring in sewers and construction zones and brothels, bringing food and scarce goods back to a hungry homeland.

"China, by its own admission, is keeping the North Koreans on life support," said a Western diplomat.

Special correspondents Wang Ting in Shanghai and Akiko Kashiwagi in Tokyo contributed to this report.

South Korean President Kim Dae Jung rejected the Bush administration's strategy of containment of North Korea during a cabinet meeting in Seoul.