If South Sudan’s famine is “man-made”, and it is, then maybe man can also unmake it. Given the country’s unstable government and America’s uncertain global leadership, however, most of the effort will have to come from China.

More than 40 per cent of South Sudan’s 11 million people do not have enough to eat — not because of drought or other natural causes, but because of their country’s civil war, which started in 2013. Mayhem and disorder have taken tens of thousands of lives and forced more than 1.5 million to flee. Meanwhile, corruption and mismanagement have contributed to a shrinking economy, by 13 per cent last year, and high inflation of close to 500 per cent.

The United States has been the biggest provider of assistance to South Sudan, but Donald Trump, who has railed against foreign aid while remaining near-silent on Africa, seems unlikely to sustain that commitment. And as with so many other crises, a stalemate at the United Nations Security Council has stymied efforts to hold South Sudan’s recalcitrant President Salva Kiir to account. Now Nikki Haley, the UN ambassador from the US, is rightly questioning whether it makes sense for America to continue paying the lion’s share of a costly and ineffective UN peacekeeping mission.

Yet the world cannot simply abandon South Sudan, for both altruistic and self-interested reasons. Some five million South Sudanese, now facing starvation or catastrophe through no fault of their own, deserve help. Their country’s instability, meanwhile, is affecting its neighbours.

The biggest outside power with the greatest practical interest in securing peace in South Sudan is China. Chinese companies have a 40 per cent stake in South Sudan’s largest oilfields, which once accounted for 5 per cent of China’s oil imports. Before the civil war, dozens of other Chinese companies were active there, with thousands of Chinese managers and workers.

It is not as if China is not involved; its large contingent of peacekeepers has even suffered casualties. It has also backed regional diplomatic efforts to solve the crisis.

Still, it has more leverage left to use. China should insist on the unimpeded delivery of aid, which Kiir’s government is blocking. It could sweeten the pot by boosting its own aid contribution, which has badly lagged behind its peacekeeping commitment and development loans. China could also lead a more robust diplomatic effort, including in the Security Council, to enforce a broader ceasefire. That could at least open the door to discussions for a broader settlement. President Xi Jinping has made expansive pledges in recent years about co-operation with Africa and China’s commitment to global leadership. South Sudan is one place where China can put its power and influence to better use.