IN 1980 Nigeria's oil revenues were $25 billion. Now the figure is $10 billion. In the shrinkage lies the explanation for the government's decision to order what Americans would call undocumented aliens out of the country -- something, needless to say, that a sovereign state has every right to do to reserve jobs for its own citizens and to cut down the social strain. The last time the Nigerians issued an order like this, some 2 million citizens from other West African countries were pushed helter-skelter, with great personal suffering, over the border. This time some hundreds of thousands of West Africans are affected, and the current military government in Lagos is taking a certain care to see that no similar face of bureaucratic indifference is presented to the world -- though news reports make plain that the exodus is not going altogether smoothly.

One wonders in any event what these unfortunate people are now going to do. The largest number of them apparently are from Ghana, where the first batch of recent returnees are being dispersed to their home villages. Yet the circumstances that drove the returnees from their villages in the first place -- broadly speaking, impoverishment in the case of Ghana, Benin and Togo, raw hunger in the case of drought-afflicted Niger and Chad -- are, if anything, worse now. The receiving governments have a political purpose in preventing additional misery from being heaped up in cities and towns, where it is at once more visible and more inflammable, but it remains misery. The movement of large numbers of people across national borders is a signal of distress; their movement back is a signal of double distress.

The famine in Ethiopia may have given many Americans the notion that distress in Africa has a special Marxist origin. It would be more accurate to say that Ethiopia's government, in its Marxist fashion, has aggravated a condition of underdevelopment and dependency that has made most of Africa a disaster area without precedent or parallel in recent times. The resources -- internal and external -- to provide life, a livelihood and the politically and psychologically necessary sense of progress have simply not been available. As a result the greater part of a continent is gripped in a pervasive and long-term crisis that has forced a focus on short-term, emergency needs. Even these are not being adequately met. Meanwhile, local authorities and foreign experts grope for ways to restore a process of development and growth. The exodus from Nigeria is one more sign of the desperation.