Nigeria's new leaders try to swim in red ink

Nigeria's new military leader, Maj. Gen. Mohammed Buhari, faces an unenviable task as he tries to restore financial and administrative discipline to black Africa's largest and perhaps most ungovernable country.

General Buhari led a bloodless New Year's Eve coup that ousted the civilian government of President Shehu Shagari. It was the country's fifth military coup and the second to displace a democratically elected government since Nigeria gained independence from Britain in 1960.

Whereas tribal and civil disorders lay behind military intervention in 1966, the main causes this time were economic.

The coup came two days after the government presented a harsh austerity budget cutting investment spending by 30 percent and imports by 40 percent.

Nigeria is in the depths of an acute financial crisis following the collapse of the international oil market. Oil revenue, which accounts for 95 percent of its export earnings, fell to an estimated $10 billion in 1982, compared with $22 .4 billion in 1980.

The resulting shortage of foreign exchange has meant that imports have had to be cut back drastically, and this has led to shortages of food, consumer goods, spare parts, and industrial raw materials.

Prices have shot up due to speculative hoarding and black-market profiteering. Inflation is estimated to have risen substantially during the last year.

The military decided that the economic crisis had been aggravated by the ''mismanagement'' of the country's political leaders. Buhari condemned the ''corrupt, inept, and insensitive'' leadership.

Although President Shagari personally enjoyed a reputation for moderation and financial honesty, the same could not be said of many of his ministers, and he sometimes appeared to have little control over them.

After being returned with a substantially increased majority in last August's elections, President Shagari attempted to improve the quality of his ministerial team by sacking all but 7 of his 45 ministers.

He also created a Ministry of National Guidance to lead a national campaign against corruption. The new ministry is headed by Yusef Maitama-Sule, one of the most influential ministers.

But this evidently did not satisfy the skeptical military. Buhari criticized ministers for being more concerned about their ''salaries, fringe benefits, and foreign travel'' than with the welfare of the Nigerian people, whom he said were having to live under increasingly intolerable conditions.

He complained that food has become more and more scarce and expensive, and that health and educational services have deteriorated sharply. Public finances are so desperate that many government employees have not been paid for up to one year.

Buhari, a Muslim from northern Nigeria, is a veteran of the military regimes that ruled Nigeria for 13 years between 1966 and 1979. He was a military state governor and a member of the military council that deposed Gen. Yakubu Gowon in 1975.

Buhari is also a soldier with economic administrative experience, having run the country's oil industry between 1976 and 1978. During this period he earned a reputation as a cautious manager but one who had an excellent grasp of this strategic sector.

Although the military can be expected to crack down more sharply on corruption, there are some doubts about whether it is better equipped than the Shagari administration to improve the country's economic fortunes.

One crucial test will be the military regime's ability to conclude an agreement with the International Monetary Fund (IMF). For more than six months, the civilian government had negotiated inconclusively over economic restructuring and a $2 billion aid program.

A main reason for the impasse was reportedly the government's refusal to contemplate devaluation of the naira and other politically sensitive measures. The government felt that devaluation would be ''political suicide'' because it would sharply increase the cost of food and other imports and would provoke a particularly hostile reaction from the urban population.

The IMF argues that the overvalued naira has facilitated cheap imports and discouraged local food production and manufacturing. On the local black market the dollar currently is exchanged at three times its official value in naira.

Negotiations to reschedule some of its $14 billion of foreign debt as well as the supply of fresh commercial credits are to a large extent dependent on Nigeria reaching agreement with the IMF.

The situation is reported to be calm in Lagos and other major Nigerian cities. Local reaction to the coup appears to have been favorable, according to agency reports.

''Daily life was becoming an impossible struggle. People are hoping that the military will take the necessary if unpopular steps to improve things,'' a Nigerian said.

The coup appears to have surprised Western observers more than Nigerians. Westerners lamented the collapse of yet another African democratic experiment so soon after elections. They say it could be several years before the military hands back power to the politicians.