BEIJING - North Korea's steps toward building nuclear weapons have sparked a debate here over whether China, North Korea's main ally, should take a more active role in the crisis and bring more pressure on North Korea to abandon its arms program.
The finding yesterday by the International Atomic Energy Agency that North Korea is violating international nuclear weapons agreements, and the agency's decision to refer the matter to the United Nations Security Council, gives China's role even greater importance.
Even as that was taking place, a senior U.S. intelligence official told Congress yesterday that North Korea has an untested missile capable of reaching the Western United States.
North Korea's decisions to expel weapons inspectors and restart nuclear facilities have been rebuffs to Beijing's calls for diplomacy over provocation and have increased pressure on China to take a more active role.
China's partnership with North Korea, formed along ideological lines and cemented by the Korean War, has never been more sorely tested.
"If your ally becomes one of your greatest threats to security, I don't think you should keep the alliance just for alliances' sake," said Shi Yinhong, professor of international relations at Renmin University in Beijing. "Whatever the consequences of this crisis, whatever the diplomatic choices China makes during this crisis, China-North Korea relations have changed forever."
The two nations signed a mutual assistance pact in 1961, at the peak of the Cold War, but now appear to be eyeing each other with suspicion.
"There is increasing recognition here that if North Korea is finally armed with nuclear weapons, it will be a big threat to China," said Zhu Feng, director of the international security program at Beijing University's School of International Studies. "I have a strong sense at this crucial moment, my government will change its mind to resort to another approach rather than just, say, use the veto right to block any U.N.-imposed sanctions against North Korea."
Such a view was unthinkable a decade ago, when North Korea's nuclear program first attracted attention. Since then, China has cultivated closer ties with South Korea and the United States. Now, China's chief regional security concern is Pyongyang.
"What worries me worst is if this will result in a nuclear arms race in East Asia," said Zhang Liankui, a North Korea expert at the influential Central Party School in Beijing. Japan, South Korea and Taiwan could respond to the North Korea threat by developing nuclear programs, he said, "the worst thing that anybody could imagine."
China has relied on diplomatic efforts by the United States, a pattern that continued yesterday when China abstained from voting at the atomic energy agency.
A Chinese Foreign Ministry spokeswoman said Tuesday that Beijing was urging North Korea and the United States to pursue talks. Echoing North Korea's demand to negotiate only with the United States, China contends that Washington and Pyongyang must engage in direct talks to resolve the standoff peacefully.
"Some American people will think China is sitting around and not doing anything, like it's watching a movie, but that's not how things are," Zhang said, arguing that diplomatic efforts by Russia and South Korea have appeared to go nowhere. "North Korea has claimed it will only deal with the U.S., not even with South Korea. ... So the ball is in America's court."
A central problem for China, leading scholars here say, is that the government does not have as much sway over its neighbor as the United States and its allies in Asia believe.
"China would like to have a strong influence on this issue, but on this matter, China does not have the power to play a key role," Zhang said.
The alliance between China and North Korea, never uncomplicated, has grown increasingly strained. While China normalized relations with the United States and embraced capitalism, North Korea stood still and accused China of betraying socialism. The North Korean leadership has purged perceived pro-Chinese factions from its ranks several times, scholars and defectors say.
Today, China's president, Jiang Zemin, and North Korean leader Kim Jong Il lack the personal connection shared by Mao Tse-tung and Kim's father, Kim Il Sung, who studied in China and fought against the Japanese in a Chinese army unit.
"There's every reason to think the relations between the two countries are quite bad, especially since the outbreak of this crisis," said Shi of Renmin University. "North Korea has given many indications that it will listen to nothing from China."
China's primary leverage now over the North is food and fuel oil, a point the Bush administration has emphasized.
Though Beijing does not disclose how much aid it gives Pyongyang, analysts estimate that China may supply enough food to feed one-fifth of North Korea's 22 million people and more than 70 percent of its fuel oil, a figure that may have increased since the United States halted oil shipments in the fall.
A senior U.S. diplomat in Seoul, South Korea, recently characterized China as North Korea's "life support." And Secretary of State Colin L. Powell said China's support accounted for 80 percent of North Korea's "energy and economic activity."
The Chinese government may be reluctant to cut off aid in part because it fears a flood of refugees - and perhaps even more out of fear of provoking Pyongyang. And there also is the weight of historic political concerns. For decades, the prevailing assumption underlying Chinese foreign policy was that a stable and militarized North Korea would act as a regional deterrent against the United States and South Korea.
"Because this assumption was forged by war, it's very powerful. It's enduring," Shi said. "It's very difficult for people who are accustomed to this historical assumption to do anything but do nothing."