As an emerging power increasingly seeking a global role, Beijing should recognize that its economic concerns must give way to the imperative of stopping the slaughter of the people of Darfur.

Sudan brings that challenge to a head. The China National Petroleum Company is the largest investor in Sudanese oil fields, which produce the type of crude that suits Chinese refineries. Most of China's holdings are in southern Sudan, but some are in the western region of Darfur. Over the past two years, the Sudanese government and its proxy militia have launched a massive campaign of ethnic cleansing in Darfur that has forcibly displaced nearly two million people and left tens of thousands dead.

Stopping the slaughter, rape, and displacement in Darfur has become an urgent priority for the United Nations Security Council. Yet China, fearful of jeopardizing its oil investments, has repeatedly used veto threats to weaken pressure on the Sudanese government.

Sudan boasts a sophisticated leadership, much of it Western educated with many ties abroad. These ringleaders of the Darfur slaughter would immediately feel any restrictions on their travel or seizure of their overseas assets. Yet China has refused to countenance such targeted sanctions. Deprived of that leverage, the Security Council has found itself in the position of supplicant. It has authorized the deployment of military observers and a small protective force, but only to the extent allowed by Khartoum.

The Sudanese government, in turn, has insisted that only troops from the African Union be deployed. But the A.U. is a new institution which lacks the logistical experience, available troops, and political will to police a difficult and remote area the size of France. Indeed, of the 3,300 troops permitted so far, the A.U. has managed to deploy only about 1,000. That miniscule, underequipped force is incapable of providing real protection. Efforts to supplement it with a more powerful U.N. force have met resistance.

The Security Council's next major decision on Darfur will come at the end of this month, when a commission of inquiry is likely to recommend that the council refer the situation in Darfur to the International Criminal Court. When I recently spoke with Sudanese leaders in Khartoum about possible ICC prosecution, they were visibly worried. Clearly these worldly officials are not eager to spend their dying days dodging arrest in the Sudanese desert. ICC involvement would have an immediate deterrent effect, helping to save many lives.

But will the council endorse ICC action? Ordinarily the Bush administration, which opposes the ICC because of its theoretical ability to prosecute Americans, might be expected to block referral to the court. However, Washington has described the atrocities in Darfur as genocide. Rather than reward the killers in Khartoum with a veto of an ICC referral, Washington may be convinced to abstain.

With France and Britain likely to support ICC referral for Darfur, and Russia at worst to abstain, the fate of the proposal may depend on whether the Chinese government exercises its veto. In other contexts, the Chinese government has been encouragingly supportive of the ICC, such as last May when it helped defeat Washington's efforts to exempt U.S. peacekeepers from the court's jurisdiction. So why would Beijing consider protecting killers who have been responsible for massive crimes against humanity if not genocide? Because it fears that prosecution up Sudan's chain of command might implicate its business partners.

China's fears for its oil interests are probably overblown. Any government in Khartoum will have legal and economic reasons to respect China's oil investments. With these contracts in place, China has less reason to fear the increased Western competition that would come from stopping the Darfur killings and ending Sudan's pariah status—competition which, in other contexts, has been difficult for Beijing.

Moreover, in light of the signing earlier this month of a peace accord in southern Sudan, many of China's oil investments will soon be in areas controlled by the rebel Southern People Liberation Army—a group that sympathizes with the people of Darfur far more than do officials in Khartoum.

Whatever the economic calculus, the bottom line is that China's responsibility as a permanent member of the Security Council requires it to oppose the ethnic cleansing in Darfur. As the U.N. high-level panel on security threats recently argued, permanent council members should never use their vetoes when crimes against humanity are at stake. As an emerging power increasingly seeking a global role, Beijing should recognize that its economic concerns must give way to the imperative of stopping the slaughter of the people of Darfur. The alternative—quenching China's thirst for oil with the blood of the people of Darfur—is too awful to contemplate.