Before I left for southern Sudan two weeks ago, China found itself on the defensive again over its links to the Khartoum government. A U.N. report found that Chinese-made bullets and other ammunition had been shipped to Darfur and that Sudanese forces had used them in battles against Darfur rebels over the past two years,in clear violation of an arms embargo.

China mounted an aggressive PR campaign at the U.N. to block the report's publication, as Foreign Policy reported. Never mind that Chinese arms dealers didn't know where their weapons would be used, or that security firms in other countries (ahem) have also violated bans on doing business in Sudan. The U.N. report fit neatly into the narrative that China is an ally of African regimes that the West finds deplorable - or, as some activists might describe Beijing's support of Khartoum, "genocide's enabler in chief."

Proponents of that narrative might be surprised at what's going on in southern Sudan, which fought a 22-year war against Khartoum and is about to begin a bitter (and possibly bloody) breakup with the government. On my recent visit I found Chinese firms deeply invested in southern Sudan, and not just in building roads and pumping oil.

Indeed, China has become one of the most visible and reliable friends of a Juba government that's desperately trying to stand on its own feet. Chinese firms are engaging in an array of projects whose diversity is probably matched only by the United States:

• bidding to build a pipeline that would pump southern Sudanese oil out to a port in Kenya, skipping the Khartoum-controlled pipeline through the north;
• building a major new laboratory at the University of Juba;
• operating one of Juba's better hotels;
• inviting a dozen southern government ministers to China for a high-profile tour.

One Western diplomat told me that the southern Sudanese government had caught "China Fever." As for China and its old friend, Khartoum, the diplomat said, "Khartoum is telling them, 'You're hated in the south. Cancel all your contracts.' But then China comes down here and see how welcoming they are and they change their mind."

Time to update our playbook on China in Sudan.

Shouldn't this budding relationship rankle Khartoum? Probably a bit. But both Khartoum and Beijing are nothing if not pragmatic. Each knows that it has what the other wants. It's a relationship that's built on stronger stuff than any anti-Western sentiment that some observers ascribe to it. But it's also less complicated.

"They're not playing one side against the other; they're playing their own side," another Western diplomat told me. "They're making business."