(Reuters) - China is under increasing pressure from the United States, South Korea and Japan to persuade ally North Korea to end its belligerent behavior.
What can China realistically hope to do? Here are some questions and answers:
WHAT'S DRIVING CHINA'S RESPONSE TO THE CRISIS?
After an initial muted response to North Korea's shelling of a South Korean island on November 23, China has engaged in a flurry of diplomatic efforts to try to fend off criticism that it is siding with its old ally Pyongyang against the United States, Japan and South Korea.
China's President Hu Jintao warned U.S. President Barack Obama on Monday that tensions in the Korean peninsula could "spin out of control."
Hu's phone conversation follows meetings in late November between senior diplomat, State Councillor Dai Bingguo, and South Korean President Lee Myung-bak, and Chinese Foreign Minister Yang Jiechi's meeting with North Korean ambassador Ji Jae Ryong in Beijing.
"I'm totally sure that Beijing will not sit and watch," said Zhu Feng, an international relations professor at Peking University.
"Compared to the Cheonan incident, Beijing has been more proactive. But this is the Chinese way -- quiet diplomacy," he added, referring to the March sinking of a South Korean corvette, blamed by an international investigation on a North Korean torpedo.
For the most part, the stance from Beijing has been cautious, urging calm and avoiding taking sides.
For China's leaders, the tricky balancing act calls for diplomatic whispering, not shouting.
China wants to avert a spiralling standoff between its two neighbors. It also hopes to avoid estranging North Korea, a long-time ally Beijing sees as a crucial buffer against U.S. influence in Northeast Asia.
North Korea depends on China for economic and diplomatic support, but can bristle against overt pressure from Beijing and does not automatically bend to its wishes.
On the other hand, South Korea is an important trade partner of China. Behind Seoul stands the military power of the United States, which Beijing worries about.
WHY THE CALL FOR TALKS?
China does not want to wade into the rights and wrongs of the North Korean bombardment. Nor does it want to be seen as washing its hands of the crisis. Its answer is to urge talks.
Beijing seems to have absorbed some lessons from a confrontation earlier this year, when South Korea said it had firm evidence North Korea was responsible for torpedoing a South Korean navy ship, killing 46 sailors.
Beijing's reaction to the sinking of the Cheonan was slower and more tepid, angering South Koreans. This time, it has acted more quickly and vocally, apparently in the hope of escaping charges from its neighbors of indifference and inaction.
But a broad call for talks may not be enough to achieve that.
"China must have the courage to change criticisms from abroad that it is inactive and ineffective in Korean peninsula issues," Li Xiguang, a professor at Beijing's Tsinghua University, wrote in the Chinese newspaper the Global Times late last month.
WHAT COULD THE TALKS ACHIEVE?
China has called for talks among chief negotiators in the six-party talks, a stalled process aimed at ending North Korea's nuclear weapons program in return for aid and other assurances.
Those talks bring together North and South Korea, China, the United States, Japan and Russia -- all key actors in the current dispute -- and which have been in mothballs for over two years.
A meeting now would be unlikely to achieve anything substantial, but China believes that sitting down together and talking could help drain away the volatility.
"China's mentality is always this -- you should not ask me to act unilaterally," said Peking University's Zhu. "That's why China always appeals for the emergency consultations. They see it as shared responsibility."
Chinese State Councillor Dai Bingguo, who advises leaders on foreign policy, reiterated in a statement on Monday that China will not interfere in the internal affairs of other countries and pledged to refrain from threats or force in dealing with other countries.
"We've only followed a few principles when it comes to international relations and, for the past few decades, they have proven to be effective," Dai said. "Not to engage in the interference of internal affairs, and refrain from the use or threat of force; not to show favoritism and not to form cliques."
But Dai also said that China will be "actively involved" in global issues relating to the North Korean and Iranian nuclear programs, as well as the Arab-Israeli conflict and Sudan's Darfur -- underscoring the dilemma facing China's foreign policymakers.
"China is a responsible participant in the international system," he said. "China is willing to take a more active attitude in future to participate in this process, including participation in international rule-making and is willing to take on more global responsibilities in line with the nation's power."
IS NORTH KOREA LISTENING TO CHINA?
This is hard to say. Ties between these two countries are intensely secretive and Pyongyang can be a prickly partner.
China has not openly said that North Korea favors its call for emergency talks, and if Pyongyang was on board, Beijing would be likely to advertise that point.
For now, at least, North Korea may be too preoccupied with the confrontation with Seoul to pay much heed to China.
The United States and its regional allies, South Korea and Japan, have urged China to press North Korea harder. But China will step gingerly.
"The Chinese government is doing its fair share. What else can you do? Punch on the table or shout at North Korea? You would make the whole thing worse," said Wang Dong, a professor of international relations at Peking University.
"If we behave like how the U.S. behaves, you would push North Korea into a corner."
WILL HU'S COMING VISIT TO THE U.S. MAKE A DIFFERENCE?
Unlikely.
China would be reluctant to compromise on North Korea to avoid appearing weak before an increasingly nationalist and demanding Chinese public, which remains largely supportive of the North Korean regime, Peking University's Zhu said.
Zhang Zuqian, a researcher at the Shanghai Institute for East Asia Studies, told the Global Times that it would not be suitable for China to openly apply military and economic pressure on North Korea.
"Otherwise, even if North Korea makes temporary concessions, it will sow the seeds of endless trouble," Zhang said. "On the one hand, North Korea would harbor hatred of China.
"On the other hand, it would be a sweetener for the United States so that in the future they would endlessly pressure China to dance to the tune of the West."
