Fourteen months after seizing power vowing to conduct a "holy war" that would reestablish this country as one of Africa's most advanced and prosperous states, Ghana's once-radical rulers are moderating their ambitions in keeping with the country's dire economic plight.

Once the richest and most literate nation in black Africa, Ghana has been reduced to bare subsistence, its elites either disaffected or gone abroad to survive, its once prosperous farmers refusing to grow cash crops in exchange for worthless money.

Flight Lt. Jerry John Rawlings, the 35-year-old chairman of the Provisional National Defense Council, and his associates are beset by problems inherited from five military and three civilian government and compounded by their own indecision. But it has been Nigeria's deportation of hundreds of thousands of Ghanaians in January that seems to have shocked the regime into gingerly embarking on moderation.

The Nigerians' expulsion created a current of sympathy in the West, and western aid, often from nongovernmental organizations and charities, has allowed Ghana to cope. For the first time, Rawlings and his key advisers began saying nice things about the West. Rawlings even criticized the local press for its antiwestern bias, a clear signal that he knew the lion's share of the aid was not coming from the Soviet Bloc.

Faced with the priority of meeting the needs of the deportees from Nigeria, Rawlings has postponed, if not canceled, many of the regime's plans to extend the already swollen public sector that would have nationalized all import trade and the transportation system and extended government control of private banks.

Even the International Monetary Fund, long denounced as the ultimate tool of American imperialism, has been accepted. Onetime archcritic Kwesi Botohway, the Marxist finance and economic planning secretary, returned from Washington in late February with a memorandum of understanding with the fund that--pending agreement on final terms next month--could provide $300 million in assistance and the first serious hope of rescuing the economy.

The quarter century of recent history since Ghana's first independent leader, Kwame Nkrumah, inherited power from Britain in 1957 seems a textbook case of how to ruin an economy.

Along with independence came foreign exchange reserves of more than $300 million, thanks to careful colonial husbanding of Ghana's diamonds, gold mines, timber and cocoa.

But once the inheritence was quickly run through, Ghana's economic decline began. Freed for nationalistic reasons from the pound sterling, Ghana's currency proved increasingly vulnerable--in part because of bad management and corruption, in part because of the magnetic attraction of the strong, French-backed franc currencies of the former French colonies that surround it.

Revolving door governments, each adding another parasitic layer of civil servants, further weakened the economy. So, too, did special import licenses that provided a killing for the happy few at the expense of the country.

Importing rice, corn, sugar and other staples at the artificial exchange rate made producing them locally uneconomical. The once-rich agricultural sector, especially the foreign exchange-earning cocoa crop, in many cases literally went back to bush.

Rawlings, who in a fit of moral outrage had seized power in 1979 only to abandon it to a corrupt civilian regime after 112 days, staged the Dec. 31, 1981 coup determined to carry out thoroughgoing revolution in Ghana.

Part Sunday school preacher, part down-to-earth soldier, Rawlings enlisted many left-wing intellectuals in his crusade.

He borrowed $96 million from Libya for badly needed oil, but despite his enemies' accusations, he seems too much a Ghanaian nationalist to be taken in by the kinds of machinations Libya's Col. Muammar Qaddafi has practiced in less sophisticated African countries.

Although Rawlings has not spelled out the gradual shift away from the doctrines of his revolution, the regime has recognized that anticolonialist rhetoric has little relevance to the mess Ghana faces today.

Inflation last year was 116 percent by conservative official estimate and is soaring once again under the pressure of the unskilled thousands returning from Nigeria without jobs or money.

Foreign exchange remains so tight that raw materials are available only in eyedropper quantities. Industrial production has sunk to 10 percent of capacity. World prices for cocoa, which accounts for some 60 percent of foreign exchange earnings, continue to fall. A bloated bureaucracy swallows between half to two-thirds of the government budget, which is burdened with a growing deficit.

Industrial diamond production declined a third last year to reach its lowest levels since independence, and gold extraction in 1982 was only a third of 1960 output.

The gross national product has declined in each of the past five years, most markedly in 1982. Once a food exporter, Ghana cannot feed itself. The rains failed last year and are late in many parts of the country this winter.

Some foreign missions and nongovernmental organizations fear famine conditions before the new crops of cassava, yams, corn and other staples are harvested in July.

There is next to nothing on store shelves--no batteries, no toilet paper, no soap, no regular supply of beer, no light bulbs, no matches, no vegetables, no bread, no tires, no drugs, no textiles, no fertilizers or insecticides.

The transportation system has gone to ruin and is incapable of moving cash crops to market. Hundreds of thousands of acres of rubber and palm oil plantations have been lost.

Cocoa production, once the highest in the world, has reached its lowest level in generations because farmers prefer growing subsistence crops to selling at artificially low prices to a government that pays in unredeemable chits. By government estimate, between 1980 and 1982 production of corn declined by 48 percent, rice by 72 percent, cassava by nearly 23 percent, yams by 44 percent and poultry by 81 percent.

The whole Alice-in-Wonderland nature of the economy rests on the sacrosanct official value of the currency called the cedi, which is pegged at 2.75 to the dollar although it is traded at 30 times that on the black market. The Rawlings regime hates the word "devaluation," which has come to signify an invitation to stage a coup d'etat.

No one knows that better than Rawlings, for he and his friends overthrew democratically elected president Hilla Limann Dec. 31, 1981 because he was about to devalue the cedi in exchange for help from the IMF, the World Bank and other international and private lending institutions.

Finance Secretary Botohway still refuses to devalue the cedi formally, but has dreamed up an elaborate backdoor devaluation involving multiple exchange rates providing for bonuses for exports and surcharges on imports. It is that system, to be administered by the rigorous Bank of Ghana, that the IMF has approved tentatively.

So vital is accommodation with the IMF deemed that the regime stifled its deep-seated suspicions that the United States was behind a particularly amateurish plot, complete with detailed assassination list, that was uncovered Feb. 28. The Reagan administration, it was feared, could sabotage IMF help because of its 22 percent participation in the Washington-based lending institution.

Sources close to Rawlings, noting the arrest of a man in possession of an American passport and the U.S. consular help provided his American companion who later left Ghana, said only that some strands of circumstantial evidence pointed to involvement by people claiming to be working on behalf of the U.S. Embassy.

By current Ghanaian standards--which include often crude and unsubstantiated anti-American tirades in the press--that amounted to almost a clean bill of health.

The political turning point marked by the decision to come to an understanding with the IMF was made possible by the elimination of rivals over the months.

Initially Rawlings included radicals and moderates in the Provisional National Defense Council. The result was paralysis. Indeed the seven original council members were unable to agree on four others supposed to fill out their ranks--or even on meeting.

By now only Rawlings and one other founding member remain on the council. In October and November first the moderates, then extremists either quit or were arrested or driven into exile in a series of showdowns.

In recent weeks Rawlings has moved forcefully to curb the excesses of the workers' defense committees and peoples' defense committees, the work site and community groups he established both to provide a disciplined base for the government and to fulfill his promise to give "power to the people."

Although determined not to end the ferment of the workers' and peoples' committees, Rawlings abruptly decreed that they could no longer round out their salaries by selling for personal profit the cigarettes, refrigerators and other goods they helped produce.

Despite his increased skill in surviving the Ghanaian obstacle course, Rawlings is still vulnerable, and not just to armed plotters.

Politically, he remains at the mercy of the publication--expected any day now--of a report by a special investigating board he was forced to set up to look into the murders of three judges and a retired Army major last June 30.

In many other African countries, such happenings are considered an ugly part of everyday life. But here, where all strata of society share a genuine respect for the law and for the independent judiciary inherited from the British, the murders aroused deep-seated moral indignation.

Four soldiers who confessed they carried out the murders were arrested. Council member Joachim Amartey Kwei was accused of having issued the orders. But he, in turn, gave public testimony accusing Kojo Tsikata, perhaps Rawlings' closest collaborator, of having masterminded the murders.

If the report indeed does implicate Tsikata, a Sandhurst graduate turned professional revolutionary in Angola, Rawlings may be forced to drop him as the price for his own survival.

Rawlings remains well thought of in the decaying industrial cities of Tema and Takoradi and the slums of Accra, especially among the workers his propagandists extol as "the vanguard of the revolution." But exhortatory rhetoric has its limits. Ghanaians who in the early days answered Rawlings' call to clean streets and ditches now pay less attention to his reiterated appeals for sacrifice and productivity.

Even the National Union of Ghanaian Students, a radical stronghold since Nkrumah founded the national university, voted in a moderate slate partly in reaction to Rawlings' forced enlistment of students to move the cocoa crop to market last year, and partly because of his decision requiring them to contribute two years of national service.