"Not on my watch," wrote President Bush in early September 2001, in the margin of a report on President Clinton's limp response to the 1994 genocide that took 800,000 lives in Rwanda.

Now unfolding on Bush's watch is another genocide—so the administration has called it—in Darfur, the rebellious western province of Sudan. Government-backed Arab militias known as the Janjaweed have killed at least 70,000 black villagers—with estimated deaths ranging above 300,000—have raped thousands more, and have driven some 2 million into refugee camps, many in neighboring Chad. Sudan's government has also sent its air force to bomb rebels and civilians in Darfur.

What has President Bush done to stop the slaughter in Sudan? Until recently, more than any other world leader, even according to human-rights groups that habitually assail U.S. policies. The administration was instrumental in bringing about the December 31 "permanent cease-fire" in the other Sudanese conflict between the Khartoum regime and rebels in the south, which had claimed 2 million lives since 1983. It has also pressed—in vain—for international sanctions to force Sudan to stop the killing in Darfur.

But the body count continues to rise, at an estimated 10,000 a month. And now human-rights advocates fault the administration—as do some more-conservative voices—for vowing to block a proposal to authorize the International Criminal Court, at The Hague, to investigate war crimes in Darfur. The administration is pushing instead for the creation of an ad hoc, regional court, an idea dismissed by many as doomed to delay and ineffectiveness.

No court would be as effective as direct military intervention, an arms embargo, or tough economic sanctions. But the world has balked at such costly steps. The only peacekeepers in Texas-sized Darfur so far are some 1,000 lightly armed African Union troops, much too small a force to have a serious impact. So by default, much of the world sees the ICC as the best hope for at least putting Sudanese leaders in fear of prosecution.

A special U.N. investigative commission recommended in late January that the Security Council authorize the ICC to investigate "crimes against humanity" in Darfur. (The ICC would have no jurisdiction without a Security Council vote, because Sudan has not ratified the 1998 treaty creating the court.) The commission stopped short of finding "genocide," an especially uncomfortable word for European leaders who—for all their human-rights rhetoric—have not lifted a finger to stop the atrocities. France and China seem more interested in protecting their Sudan oil investments, and Russia in protecting its Sudan arms sales.

The Bush administration has shown more seriousness. But now, much of the publicity about Darfur has shifted from Janjaweed massacres, Sudanese complicity, and European cynicism to the Bush administration's increasingly obsessive crusade to strangle the ICC.

Some background: The Clinton administration supported the creation of a permanent international tribunal to punish flagrant human-rights violators whose own governments support or condone their activities. But U.S. negotiators sought to require a Security Council vote before any ICC investigation could begin, to rule out politically motivated prosecutions of U.S. officials or former officials. Other ICC founders rejected any such limitation on its jurisdiction as unnecessary and unwarranted. Clinton signed the ICC treaty anyway to signal U.S. sympathy for its goals. But he declined to submit the treaty to the Senate for ratification unless and until it could be amended to meet U.S. objections.

Bush, on the other hand, has displayed ever-greater hostility to the ICC. He "unsigned" the treaty in May 2002, a few months before the ICC opened for business. His administration has pressed allies and aid recipients for bilateral commitments never to surrender U.S. nationals to the ICC, under any circumstances, and has withheld tens of millions of dollars in aid from more than 20 countries that have refused to sign such commitments.

Pierre-Richard Prosper, Bush's ambassador at large for war crimes, took this hostility even further by announcing on January 27 that the U.S. would block any ICC investigation of Darfur because "we don't want to be party to legitimizing the ICC."

Such talk carries what began as a prudent wariness of the ICC past the point of ideological fixation. As Jack Goldsmith, who was a high-level, Bush-appointed Justice Department official until last summer and now teaches international law at Harvard Law School, wrote in a January 24 Washington Post op-ed: "The United States has never opposed ICC prosecutions across the board. Rather, it has maintained that ICC prosecutions of non-treaty parties would be politically accountable and thus legitimate if they received the imprimatur of the Security Council. The Darfur case allows the United States to argue that Security Council referrals are the only valid route to ICC prosecutions and that countries that are not parties to the ICC (such as the United States) remain immune from ICC control in the absence of such a referral."

Such an approach, Goldsmith added, "would signal U.S. support not only for the United Nations but for international human rights as well, at a time when Washington is perceived by some as opposing both." It might also add leverage to U.S. efforts to shame France and others into approving economic sanctions.

Goldsmith seems right. But that's not quite the end of the argument. Apart from the risk that the ICC might someday pursue Americans, Prosper told National Journal's Corine Hegland (see NJ, 1/22/05, p. 215), the ICC is a bad instrument for redressing the wounds of war-torn societies. Rather, argued Prosper, local governments have a responsibility to step in that "should not be taken away from them."

Such is the rationale underlying the administration's proposal that the U.N. and the African Union create a regional court to investigate the Darfur atrocities. It would be located in Arusha, Tanzania, at the headquarters of the ad hoc U.N. tribunal that is still prosecuting suspects in the 1994 Rwanda genocide.

The regional-court approach is also championed by Ruth Wedgwood, who teaches international law at Johns Hopkins University. "The African Union is interested in strengthening its human-rights institutions, and it's a particularly poor time to tell them that Africa isn't capable of handling prosecutions for genocide, even with international assistance," she stresses. A regional tribunal, Wedgwood adds, may have more credibility among Africans and a better chance of getting custody of Sudanese defendants. The ICC, on the other hand, "could be limited by the U.N.'s official view that the events in Darfur are not genocide," and the court "already has a full agenda with investigations in the Congo, Central African Republic, and Uganda."

Indeed, some other experts say, for the European-dominated ICC to be hauling people from yet another African country to be jailed and tried at The Hague might smack of colonialism.

All true. But the same Prosper who now cites the Rwanda tribunal as a model assailed it in 2002 for lack of professionalism, inefficiency, unwarranted expense, and interminable proceedings. He demanded that it close down by 2008 regardless of whether suspects in the Rwanda genocide remain at large.

Don't bet on a new tribunal run mainly by the African Union—most of whose member governments are hardly known for competence or integrity—to do much better.

Only the ICC is ready, willing, and able to start investigating war crimes in Darfur now. And only the ICC—which was originally conceived by Americans as well as many others as a permanent institution to handle precisely this sort of case—has the international clout and the staying power to put much fear into the Sudanese officials who are responsible for these atrocities, and who could call them off.

These officials might not fear an ad hoc, African-run tribunal likely to close up shop within a few years. But according to human-rights activists who have toured the region, Sudanese officials are very much afraid of the ICC, which could dog them for the rest of their lives.

After-the-fact prosecutions might seem a pale substitute for direct action—or even a largely symbolic exercise designed to expiate the world's guilt. But "ending the impunity," says Jemera Rone, Sudan researcher for Human Rights Watch, is a key to ending the killing.

Doing something beats doing nothing. And nothing is about what the United States and the world are doing now to stop the genocide taking place before our eyes. On Bush's watch.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.