FEW GOVERNMENTS are bloodier than Sudan's. The Islamist dictatorship in Khartoum routinely abuses human rights; it condones slavery; it has sought to impose Sharia law on the non-Islamic south, deepening a civil war that has claimed 2 million lives since fighting broke out in 1983. Yet not everybody supports the United States' embargo of Sudan. Last week a European Union delegation was in Khartoum, claiming to have seen "some encouraging action" on human rights. Meanwhile European firms are anxious to join Canadian, Malaysian and Chinese rivals in exploiting Sudan's oil resources.

If it were not for this oil-inspired softness on Sudan, an end to the country's murderous civil war might just be conceivable. Not long ago, both sides seemed exhausted after years of stalemate on the battlefront; and the north appeared to concede that its ambitions to impose Sharia on the south were hopeless. Two sets of peace talks showed modest signs of life; in September Western donors boosted one of these by paying for a permanent secretariat to oversee negotiations in Kenya.

Now, however, peace hopes have been buried by the recent completion of an oil pipeline, promising $200 million or more a year in revenues. Rather than negotiate, the north declares that it will use its new oil wealth to stock up on military gear and win a victory on the battlefield. The government is bent on ethnic cleansing of territory surrounding other, as yet unexploited, oil fields. Once it has control of these, it will purchase yet more tanks and missiles.

Talisman Energy Inc., the Canadian company that operates the new pipeline, has rightly become the target of a divestment campaign: It is listed in New York and Toronto, and a quarter of its stock is owned by Americans. Its Malaysian partner, Petronas, is not listed in the United States; but China National Petroleum, which owns 40 percent of the project, plans a share issue on the New York Stock Exchange with the help of Goldman Sachs. France's Total, whose shares are already traded in New York, hopes to be in on future oil projects in Sudan. So does Sweden's Lundin Oil AB, which is listed on the Nasdaq market.

Divestment campaigns are not enough. Western governments should present a united front in condemning Khartoum, not seize upon minor human-rights concessions as an excuse to warm relations. The Canadian government last month announced that it might punish Talisman for its involvement in Sudan; this triggered an immediate fall in the company's stock price. Europe's governments should warn their oil companies away also.

Over the past 16 years, the West has funneled billions of dollars of aid into Sudan's south, hoping to ward off disease and starvation. It should not now let its oil firms prolong the country's agony.