The Third World is gone. It has been vanishing for a long while, but now it has completely disappeared. Oh, the countries once assigned to the Third World are still there, but the concept of the Third World is no longer connected to any reality.

We will still deal (quite obviously) with the Brazils, Indonesias, Nigerias and Indias. But the idea that these many nations represent anything like a single bloc with similar characteristics and interests is shattered forever. It is yet another casualty of the end of the Cold War. The term Third World originally reflected a globe divided into the First World (the industrialized democracies), the Second World (the Communist bloc) and everyone else. Bingo. The implosion of the Communist bloc obliterates this geopolitical arithmetic.

What this means is that developing countries, as a group, have lost much of their political leverage. The Third World was once viewed as a vast terrain on which the free world and the Communist bloc struggled for power and influence. In this situation, countries could subtly (or not so subtly) tout their importance in the Cold War contest as a way of winning more foreign assistance. No longer.

"Their value as pieces on the strategic and ideological chessboard has significantly depreciated," writes political scientist Mark Falcoff in the current issue of The American Enterprise magazine. "These countries will find it increasingly difficult to extract concessions and resources from Western governments."

What we will see is rich nations everywhere trying to stabilize their regions with some aid and trade concessions to their poorer neighbors. The United States is already focusing on Latin America, Japan on China, and Western Europe on the former Soviet bloc. But even here, poorer countries will increasingly be thrown back on their own resources: they're not likely to get much help unless they demonstrate the ability to organize legitimate governments and to stimulate internal economic development.

The discipline will be imposed not only by stingy taxpayers in richer countries but also by the multinational companies that control large private investment. Companies will locate plants where they think they can count on productive workers and political stability.

Of course, the Third World was always a simplistic label, whose relevance has progressively faded. In the 1950s and 1960s, there were repeated efforts by many new nations to act as a bloc and exploit their position between the free world and the Communist bloc. Colonial empires were being rapidly dismantled. Britain freed India and Pakistan in 1947 and Nigeria in 1960. In 1955, President Sukarno of Indonesia hosted the first conference of 29 nonaligned nations in Bandung. Many more conferences followed.

It was always easy to denounce imperialism and ask for more foreign aid. Unity on other issues was strained or nonexistent. Countries' interests and circumstances diverged too much. "The commonalities between Mexico and Mali are hard to find," says John Sewell, head of the Overseas Development Council, a Washington think tank.

What has also fragmented the Third World are huge differences in economic growth. In its World Development Report, the World Bank -- the largest international development agency -- publishes the following table. It gives average annual growth rates of per-person income for poor regions. (East Asia generally stretches from Indonesia through Thailand to China; South Asia covers Sri Lanka, India, Pakistan, Bangladesh and nearby nations.)

........................1973-80........1980-89

Sub-Saharan Africa..........0.1........... -- 2.2

East Asia...................4.7............6.7

South Asia..................1.7............3.2

East Europe.................5.3............0.8

Latin America...............2.6........... -- 0.6

Middle East, North Africa...2.1............0.8

Here is a snapshot of progress and poverty. With rapid population growth, poverty has deepened in sub-Saharan Africa, and disruptions in food production threaten famine. In Latin America, middle-class living standards have declined, and the poor have gotten poorer. Meanwhile, much of East Asia has boomed. South Korea's income per person has climbed 7 percent a year since 1965. In 1988 it stood at $3,600. South Korea has more in common with the United States than with Zaire (per-person income, $170).

You can make two generalizations about the past 30 years. First, there have been big gains in reducing poverty. Incomes in most countries have risen. Diets and life expectancies have generally improved. In Colombia, the mortality rate for children under 5 fell from 135 per thousand in 1965 to 42 per thousand in 1985. Second, massive poverty remains. The World Bank counts as the poorest of the poor anyone who lives on $1 a day or less. By this measure, a billion of the world's 5-plus billion people are in poverty.

One thing we have learned is that foreign aid doesn't permanently cure poverty. Countries do it on their own or don't. Culture matters. So do competent governments with popular support that pursue sensible economic policies. When conditions are favorable, foreign aid can help.

The recognition of this reality is a further reason why the idea of the Third World no longer makes sense. The concept of a Third World implicitly presumed that all poor nations could be made wealthier with the correct doses of outside money and advice. This was a wild exaggeration. In 1989, foreign assistance to developing countries from richer nations amounted to $51 billion. But skepticism about the therapeutic power of aid means that -- aside from Eastern Europe and perhaps the Soviet Union -- there won't be a dramatic increase during the 1990s.

In many ways, some countries of the former Third World will become increasingly important as time passes. Brazil, Korea, Taiwan and Thailand are already major trading nations. Countries such as China, Brazil and India will be crucial in any negotiations on the "greenhouse effect." But as for a Third World agenda, forget it.

The label may linger until someone invents a new one to describe today's more muddled situation. The Third World still sounds nice. It just doesn't mean much.