PRESIDENT CLINTON and other leaders of the world's richest nations are expected in a few days to agree on a new plan to reduce the debt of the world's poorest. They last did this 2 1/2 years ago, congratulating themselves for an initiative that in the end didn't do much good. There's a danger now of repeating that disappointment.

Almost no one opposes debt relief for the 40 to 45 countries in question, home to 700 million people. Average life expectancy barely tops 50 years. A third of all children are stunted from malnutrition. Many can't afford to go to school. A third of all people die before the age of 40. Yet many of these countries spend more repaying old loans than they do on health care, education or other basic needs. The aid they receive is often funneled right back to the World Bank, the International Monetary Fund or developed nations to pay interest on debts that never decrease. This treadmill gives no chance for even the most enlightened governments to promote economic development.

The question, then, is not whether to write off some debts but how many and in what way. The 1996 initiative imposed so many conditions and mandated such delays that today only two countries have qualified for any help. As the IMF acknowledges, "In absolute terms, the Initiative may not be significantly reducing debt service."

The draft proposal now on the table hasn't been made public. Administration officials say it will deepen and hasten the relief. But advocacy groups argue that the improvement is so marginal that the plan still won't significantly reduce poverty or promote development. Mozambique, for example, owes about $108 million per year. The current initiative would reduce its debt to about $96 million, while the new proposal would reduce it to $80 million, according to Oxfam International. That burden would still be four times Mozambique's budget for primary health care.

There are arguments against total debt forgiveness: It could discourage future lending, penalize slightly richer countries that pay their bills and do no good unless accompanied by wise economic policies. Certainly, relief must be conditioned on sound reform and a willingness to spend more on basic health and education. But a chief limiting factor for Mr. Clinton and his colleagues seems to be cost. The developed world could easily afford to be more generous.