hen the World Trade Organization was established in 1995, no one would have predicted that poor nations' access to medicines would become its most contentious issue. Yet the current round of trade negotiations is stuck, acrimoniously, over drugs. In December, 143 of the W.T.O.'s 144 members agreed on a solution. But the lone holdout, the United States, blocked the deal. Washington's position is wrong and so obviously influenced by the drug companies that America is alienating nations whose support it needs on other trade issues.

AIDS has turned the patent question into an explosive issue. In November 2001, in Doha, Qatar, it was agreed that nations could override patents to deal with public health crises. But this ignored one big problem. Countries with little or no manufacturing capability must import drugs. The Doha rules allowed them to break patents to import, but the rules did not authorize anyone to break patents in order to export. The Geneva talks were aimed at designing rules for exports but fell apart over the issue of what drugs to include. American negotiators lobbied to limit covered medicines to those for AIDS, malaria, tuberculosis and a few diseases that affect mainly Africa. Other nations did not want to specify any diseases or the countries that can import drugs.

The more flexible position is the correct one. Once this deal is reached, it will be very difficult to reopen negotiations. No nation can predict its medical needs. During the anthrax scare, the United States was preparing to break the patent on the antibiotic Cipro and import it because it did not have the capacity to make the amount Americans might require. Washington would certainly want to be able to export smallpox vaccine if there was an outbreak in Canada or Mexico. The W.T.O. should not be in the business of tying nations' hands. If Angola decides that its children should not have to die of leukemia because their parents cannot afford medicine, it should be able to import a generic drug.

Washington argues that such an agreement would reduce incentives to invent new drugs. But the companies make their profits in rich nations. They will not stop work if poor nations, which can't buy their drugs anyway, begin to import generics.

After its debacle in Geneva, the Bush administration announced a pledge not to bring trade pressures against countries that export cheap drugs for AIDS and other poor-country epidemic diseases. This is welcome. But it is not a substitute for a flexible position on access to medicines that allows nations to protect public health as they see fit.