Non-interference in internal conflicts is one of the primary principles of Chinese foreign policy. However Beijing is showing an unusually strong interest in events in South Sudan, observes Daniel Large.
Chinese foreign minister Wang Yi, who is currently in Addis Ababa, has called on both sides to accept an immediate ceasefire, adding that he was ready to mediate between them.
China's great interest in South Sudan can only partly be explained by the country's oil, of which China is the largest purchaser.
According to Professor Large, the significance of South Sudanese oil for China has been diminishing. The country had proved to be an unreliable supplier and a risky location for China's state-owned oil giant CNPC.
The fate of Chinese oil workers, who had to be evacuated in December after the fighting began, was followed closely by their compatriots. This, says Large, is an important reason for the Chinese leadership's decision to get involved.
In the years preceding South Sudan's independence, the Chinese Communist Party established close relations with the SPLM.
Good personal contacts exist with, among others, Vice-President Machar, and ex-SPLM Secretary General Pagan Amum, who is also allied with the rebels and is currently in prison in Juba.
"China officially recognizes the legitimacy of Salva Kiir's government, but Beijing's personal ties to the rebels puts it in a special position," Large told DW.
Ethiopia currently chairs the East African "Intergovernmental Authority on Development" (IGAD) and in this capacity is leading the negotiations between Kiir's and Machar's delegates in Addis Ababa.
Casie Copeland of the ICG points out that cooperation between the SPLM and Ethiopia goes back decades.
However, unlike Uganda, Ethiopia's government is neutral in the present conflict and enjoys the trust of both sides. "It is a good sign that the talks are taking place in Addis Ababa," Copeland told DW.
Economic ties are also strong. Many thousands of Ethiopians moved to South Sudan in past years in search of work. Many of them found themselves caught up in the violence which is increasingly taking on the appearance of an ethnic conflict.
The world's chief superpower has remained largely in the background, apart from a few appeals to both sides.
The US is, however, one of the most vocal supporters of South Sudanese independence. For the time being, it is leaving active mediation work largely to IGAD, Copeland says.
Like other western nations, the US does not question the legitimacy of Kiir's presidency, she told DW.
However Washington is exerting pressure behind the scenes to try and persuade him to be prepared to compromise with the rebels so as to facilitate a peaceful solution to the crisis.
US authority in South Sudan is based less on its economic and military might and more on 'moral considerations,' Copeland says. "Both conflict parties want to present themselves as legitimate and democratic. Recognition by the US plays a big role here."