Petroleum moves machines - it is essential as both lubricant and fuel - but who would have imagined that petroleum could move literally millions of people? In the aftermath of the quadrupling of oil prices in 1973-74, there was copious discussion of the ''recycling'' of surplus petrodollars from the oil-exporting states via the Western financial system to the third-world oil importers devastated by the price explosion. What was not apparent - but has recently been demonstrated by the draconian explusion of more than a million Ghanaians and others by oil-exporter Nigeria - was that millions of people were also being ''recycled'' by the oil price increases.
* The development of Middle East oil resources, and the 15-fold increase in oil prices in 1973-74 and 1979-80, fueled a spectacular investment and building boom in the oil-rich sheikhdoms. Given their sparse indigenous populations, these nations recruited upward of 2 million temporary foreign workers from other Middle East countries, India, Pakistan, and from as far away as the Philippines and South Korea. Kuwait's population is now more than 50 percent foreign; the United Arab Emirates' nearly 70 percent. In almost every case the sending countries were oil importers whose balance of payments were ravaged by high oil prices. Millions of workers moved to oil-producing countries for work, and their overseas earnings in effect financed oil imports from these same countries.
* The Nigerian oil boom in the 1970s attracted perhaps 2 million alien workers from Ghana, Chad, and other West African nations. Most were working illegally in Nigeria.
* The Venezuelan oil boom from 1974 to 1980 similarly fueled the large-scale migration of 2 million to 4 million migrants, mostly from Colombia, also largely illegal.
* Meanwhile the oil price rise crystallized public concern in Western Europe about the ''guest worker'' programs that had imported millions of workers from the Mediterranean Basin. Animus grew against the 13 million ''temporary'' workers and dependents who had become permanent, generating frankly nativist political movements such as the ''Auslander Aus'' (Foreigners Out) movement in West Germany.
The current oil ''glut'' and weakness in price may well prove temporary - a brief dip on a long-term rising curve of world energy prices. But it is worth considering the possible immigration implications of a medium-term downward trend - or even a sharp break - in oil prices. One possible outcome: partial, perhaps traumatic, reversals of the large migration flows generated by the past decade's rising prices.
In Venezuela, tensions have been rising in recent years about the large numbers of illegal Colombian immigrants. If oil prices were to break and a serious economic crisis envelop Venezuela, it is possible that the government would seek to follow the model of fellow-OPEC member Nigeria. Ironically, the United States might unwittingly catch the backwash of such an action, given the disarray of US immigration policy and the already well-organized pathways for illegal immigration of Colombians to the US.
Even without a serious break in oil prices, excessive optimism in Mexico about continuing rises in oil prices has already led to the most serious economic crisis since the Mexican Revolution of 1910-17. The most likely immigration effects will be felt in the US, in the form of sharply increased pressures for already large-scale illegal immigration by Mexicans.
If a severe and prolonged oil price decline were to develop, even the Gulf OPEC nations would have to curtail their development investments. This would reduce their demand for additional or replacement foreign labor, and could even result in forced repatriation of foreign workers already there. Such effects would be felt in sending countries from Egypt through India and Pakistan to South Korea.
There are also likely to be many positive effects of a prolonged oil price decline. Those countries that have become dependent upon the earnings of overseas workers to finance their oil imports surely would find welcome relief, even if the out-migration option is reduced. Lower oil import bills could generate higher economic growth and hence greater demand for labor in the sending countries. But the transition period could prove painful.
The world's newspapers are full of discussion as to how the debt crises of Mexico, Brazil, Argentina, Poland, and other borrowers of recycled petrodollars can be relieved while limiting the damage to the world economy and financial system. But little or no attention has as yet been paid to the ''recycled'' millions of human beings whose circumstances grow increasingly untenable as the economic basis for their importation wanes.
The events in West Africa demonstrate the risks to political stability in both sending and receiving countries, and warn us of the humanitarian crises that can result. The human component of recycling c