KEY POINTS:
Sudan is Africa's biggest country by land area - and a long way from China. Yet in the past decade the two nations have developed a remarkably cosy relationship.
It is founded on major Chinese commercial interests in the North African nation, chiefly oil. But these ties are coming under increasing international scrutiny, to the point where human rights activists in the United States and Europe are trying to organise a boycott of the summer Olympic Games that China will host next year.
A group of more than 100 members of the United States House of Representatives sent a letter to the Chinese Government last week warning that the Beijing Olympics could be endangered if China did not change its policies in Sudan.
Hollywood actress Mia Farrow, a goodwill ambassador for the United Nations' Children's Fund, gave the campaign a publicity boost in March when she branded the games the Genocide Olympics and urged corporate sponsors to lean on China to do more to halt the conflict in western Sudan's Darfur region.
The groundswell for a boycott is embarrassing China, which wants to use the Olympics to showcase its rise in the world.
This partly explains why Beijing has shifted its diplomacy on Sudan into higher gear in an effort to show that it supports UN peace initiatives in Darfur, where as many as 450,000 people have died from violence and disease and about 2.5 million have fled their homes since an armed secessionist revolt began in 2003.
Sudan's President Omar al-Bashir reacted by unleashing a militia against the rebels.
China, accused by critics of shielding the Sudanese regime from UN sanctions, started to change its approach in October when it voted in favour of a bigger UN peacekeeping presence to buttress a weak African Union force.
Beijing has since offered more than US$10 million ($13.8 million) in humanitarian aid to Darfur and has sent 275 military engineers to help strengthen the international presence.
It has also appointed a special representative for African affairs and said that his initial focus would be on Darfur.
In Beijing, British Foreign Secretary Margaret Beckett said that despite critics' allegations, China had played quite a positive role in Sudan, particularly in seeking peace between Khartoum and rebels in Darfur.
The Chinese Government says it does not interfere in the internal affairs of other countries but has been trying to achieve a peaceful resolution.
If any country has leverage over the Sudanese regime, it is China. While Western governments and companies have shunned Sudan, China has stepped into the breach. It has supplied billions of dollars in investment, oil revenue, infrastructure development and arms sales, and provided diplomatic protection to Khartoum in the UN, where China is one of the five permanent members of the Security Council with a right to veto decisions.
Sudan has about 10,000 Chinese workers, some of them decommissioned military men charged with guarding China's investments, especially oilfields and pipelines.
Oil from Sudan makes up 5 per cent of the rapidly rising amount of crude that China must import each year to meet surging demand. More than half Sudan's oil exports go to China.
Sudanese oil production is rising quickly and China's largest state oil company owns 40 per cent - the biggest single shareholding - in the Greater Nile Petroleum Operating Company, a consortium that dominates Sudan's oilfields, in partnership with the national energy company and government-linked firms from India and Malaysia.
China joined the consortium in 1996. As its oil and other economic interests in Sudan grow so does its concern about the country's chronic instability and the threat this may pose to Chinese assets in future.
No sooner had a peace deal taken hold in the south of Sudan in 2005 when serious fighting flared in Darfur, where China also has promising oil concessions.
China's claim to be a responsible and increasingly influential global power is on trial in Sudan.
A report this month by Amnesty International accused both China and Russia of flouting a Security Council mandatory ban by sending arms to bolster the Sudanese regime. Amnesty said some of the aircraft and weapons had been used for indiscriminate attacks in Darfur. Beijing has denied that its arms supplies breach UN regulations.
China is engaged in a balancing act. On the one hand it wants to avoid international opprobrium. On the other hand it wants to protect and expand its valuable interests in Sudan.
If President Bashir continues to obstruct the UN peace initiative in Darfur, this will be a difficult balance to maintain.
* Michael Richardson, former Asia editor of the International Herald Tribune, is an energy and security specialist at the Institute of Southeast Asian Studies in Singapore.
