Sandinistas try to steady bobbing tiller of revolution. Today's contra-aid showdown will help clarify the US's stand on Nicaragua. But that country's own direction is hazy. After 3 years in Managua, Peter Ford concludes the Sandinistas are primarily ad-libbing as they go.

July 20, 1979: In Revolution Square, 50,000 jubilant Nicaraguans welcome Daniel Ortega Saavedra and fellow Sandinista leaders as they arrive on a fire engine, a day after Anastasio Somoza Debayle's National Guard has surrendered. Jan. 10, 1985: As the sun sets over the square and ceremonial cannons boom, Mr. Ortega dips his head to receive the blue-and-white sash of presidential office. On the podium sits Fidel Castro, the Sandinistas' godfather, listening to the former guerrilla's first speech as constitutional President.

Oct. 15, 1985: In a grim row, the nine Sandinista comandantes stare at television cameras. Gravely, Ortega warns the nation that ``internal allies'' of Washington's ``brutal aggression'' against Nicaragua ``have created a truly extraordinary situation.'' The government's response - a state-of-emergency decree sweeping away almost every public and private freedom on the books.

Nov. 5, 1987: 30,000 Sandinista supporters gather in the evening gloom, called to Revolution Square to hear a major announcement. Bathed in the glow of arc lights, Ortega sounds defensive as he reverses a six-year policy: The government will, after all, negotiate with the contra rebels to end the war.

Since they arrived triumphant in Managua, Nicaragua's revolutionary leaders have twisted and turned, ducked and weaved, made policy and unmade it a hundred times. Buffeted by winds of war, nearly swamped by waves of economic chaos, the Sandinistas have devoted almost all their energies to keeping their ship afloat and their hands on the tiller.

In doing so, they have eluded easy labels. But the contradictions and ambiguities in their behavior reflect distortions that make a look at Nicaragua seem like a view through a forest of broken mirrors, each set at a different angle.

Nicaraguans are poor people. Few own much more than the wood and adobe walls of their houses, a rack of clothes, perhaps some acres of land or head of cattle. For 30 years, while the Somoza dictatorship's monopoly of political and economic power deformed the country's growth, their prospects of a better life were bleak.

The Sandinista revolution, while holding out the promise of a better life, was itself a traumatic experience, twisting decades of status quo out of kilter in a matter of months. And within two years, the United States was financing an armed uprising that would grow into a full-scale war, pressing men out of field and factory into uniform, ejecting thousands of families from their homes, forcing more distortions in society. Sandinista model of society

Under the microscope of international attention, the Sandinistas have invented their model of society and applied it, in trial-and-error jigsaw fashion, as they went along. Though the framework was clear - strongly anti-imperialist nationalism, fairer distribution of farmland, more schools and health clinics for the poor, and Sandinista dominance - the overall picture has emerged piecemeal.

To confuse that picture, many different hands have been wielding the paintbrush at the same time. The Sandinista National Liberation Front (FSLN) nine-man directorate - the country's real ruling body - is a unique institution, made up of men from widely differing political and social backgrounds.

Their constant debate - between a hard line and pragmatism, between committed Marxist-Leninists and radicalized Christians, between economic priorities and political ones - explains the different approaches taken to different questions at different times.

Agricultural policy, in this predominantly agricultural country, is a case in point. Once state farms, cooperatives, and government price controls were the pillars of revolutionary policy. Today, with the failure of that approach seen in falling production and shortages, the emphasis is on private producers and market forces.

Ironically, it is Jaime Wheelock Rom'an, the only intellectual Marxist theoretician in the FSLN directorate, who has presided over this pragmatic turnabout.

Similarly, it has been Tom'as Borge Mart'inez, head of the Interior Ministry and its state-security police, and with a reputation as a hard-liner, who has proved the most flexible and open of the nine comandantes in dealing with the hostile indigenous Indians of the Caribbean coast. Sandinista flexibility has limits

But the Sandinistas' flexibility has its limits. At bottom, they have made clear in countless interviews, speeches, and actions that they regard the revolution as their revolution.

If the Sandinistas have blended idealism and arrogance in their bid to change the world, it is the arrogance that surfaces at times of stress. If the FSLN lost elections, Ortega reassured party cadremen recently, ``we would hand over the government, but we would not hand over the power.'' Because, as Mr. Borge once said, ``this revolution is eternal.'' Because the Sandinistas planned and executed it, they do not trust anyone else to manage or defend it.

That defensiveness, the secrecy with which fundamental policy choices are made, the exclusion of all non-Sandinistas from decisions about the future, are at the root of the opposition's disgust with the revolution.

In 1979, opposition leaders recall, their efforts to rally mass demonstrations against Somoza, the business and worker strikes they organized, and the international outcry they orchestrated helped oust the dictator. That, they believed, would give them a strong voice in the running of post-revolutionary Nicaragua. Their disillusion, when they discovered they had been wrong, was bitter.

Arturo Cruz, the first post-revolutionary president of Nicaragua's Central Bank, recalled arriving at an economic policymaking meeting soon after the victory. Men in uniform were sitting at the table, he found. ``It had not dawned on me until then,'' he confessed, ``that the National Directorate was going to run the country.'' Later, he joined the contras.

It was that sort of response by part of the opposition - seeking US help - that so enraged the Sandinistas.

One of the revolution's central goals, they argued, had been to rescue Nicaragua's identity and destiny from US control. After eight decades under the US umbrella, involving invasions, occupations, and US-backed dictatorship, the Sandinistas were welcomed in 1979 as national liberators.

US support for the contras has reinforced the Sandinistas' view of themselves as the sole standard-bearers of Nicaraguan nationalism in the face of foreign aggression.

That approach spawns such official propaganda epithets as ``mercenaries'' to describe the contras' unpaid peasant troops. It also awakens dark suspicions that those who are not with the Sandinistas are against the revolution, which has made them liable to victimization.

At the same time, the Sandinistas' appropriation of Nicaraguan nationalism has served to rally many citizens - perhaps most - behind their banner.

But in the face of a deep economic crisis, in which shortages of everything from food to clothes to gasoline plague every family, popular discontent is eroding the Sandinistas' support, government officials privately say.

Should peace break out, and the contras wither as a scapegoat for the country's myriad problems, the question of how the Sandinistas will recover and retain their mass base will become key.

Central to the answer will be the political confusion at the heart of the revolution, between the Sandinista party and the state. Are the Sandinistas ready to become a party like any other, competing on an equal basis for popular backing? Or will they, if they need to, use their state power to manipulate the political system and thus guarantee their continued control? Among the opposition's most persistent demands is that the Popular Sandinista Army (EPS) be depoliticized, stripped of its Sandinista title, stripped of its function as an ideological classroom for recruits, and converted into a national army.

In Central America, this demand is somewhat disingenuous. As both Guatemala's and El Salvador's Presidents have discovered to their chagrin, armies in this part of the world are political institutions, and are loath to give up being so. Both Presidents have seen their hopes for reform blocked by military officers who see their role as that of defending existing structures, economic interests, and ways of life.

Army to remain under Sandinista control

The EPS will clearly remain a Sandinista Army for as long as the Sandinistas hold office, and afterward too, as Ortega made clear last December. Should another political party win elections, he warned, ``the moment they try to convert the people's army into an army of the capitalists, the people will rise up, and at the head of the insurrection will be the Sandinista Front.''

The chances of easing Sandinista control over civilian structures of the state, however, seem greater. The first test will come with the municipal elections, which officials say will likely be held by the end of this year.

Should the peace plan still be in force, and should elections be held, even the opposition parties that boycotted the 1984 presidential poll are expected to run.

The Sandinistas can thus expect to lose a significant number of municipalities, and the moment of truth for their professed pluralism will have arrived.

In recent months, to comply with the peace pact, the Sandinistas have markedly relaxed their iron grip on Nicaraguan society. With no state of emergency, and no censorship, opposition newspapers and radio stations are using their new-found freedoms to be ruder to the authorities than any other Central American press is.

Opposition political parties and trade unions are growing bolder in organizing anti-Sandinista demonstrations. And they are now free to mount efforts to do so.

Sandinista officials say they are unconcerned by the displays of discontent. But with the war continuing, and US funds still flowing to the contras, the government has clearly found it difficult to open up space to its opponents.

Sandinista leaders insist the new liberalization measures are merely a return to the revolution's initial ideals, before the war forced it into a defensive shell. But the government appears to have concluded that the revolution itself, let alone its ideals, is threatened if the war goes on.

EPS officials are confident that the contras can never beat them, but they speak less often than they used to of the rebels' ``strategic defeat.'' At the same time, the war has taken a disastrous toll on the economy: Inflation rages at 1,500 percent a year, and living standards have fallen to the level they were at 30 years ago.

The Sandinistas can begin to tackle that catastrophe only in peace. Meanwhile, as people grow poorer, their faith in their government erodes.

And the war goes on, undeterred by a World Court ruling from The Hague that the war is illegal under international law, unhindered by the Central American peace plan that asked for an end to contra funding.

Revolution reaches another turning point

As usual, Sandinista leaders are tight-lipped about their plans should the US Congress vote more aid for the contras. But the revolution has reached another of its many turning points.

Will Managua batten down the hatches if the contras win more military funds? Or will it turn the other cheek, and give flexibility more time to reap its rewards? The answer will decide which snapshot of Sandinista Nicaragua fades faster in the harsh light of world attention and political battle: the comandantes barricading themselves behind a state of emergency, or coming out to talk.

Nicaragua and the US 1838: Nicaragua wins independence from Spain. 1855: US businesses establish operations. 1912: US Marines intervene to overthrow nationalist government, which threatened US interests; establish military bases. 1925: Civil war. More US Marines arrive. 1927: Augusto Sandino takes up arms against Marines. 1933: Marines withdraw, leaving newly formed army, the National Guard, under the leadership of Anastasio Somoza Debayle; Sandino killed. 1937: Somoza elected President; 40-year dictatorial family rule follows. 1961: Rebel movement, the Sandinista National Liberation Front is formed. 1979: Sandinistas oust Somoza regime. Carter administration starts economic aid. 1981: Reagan administration suspends aid. 1982: US gives rebels $19 million in covert aid; Sandinistas impose state of emergency. 1983: US officially gives rebels $24 million. 1984: Daniel Ortega Saavedra is elected President; Reagan administration calls vote a ``Soviet-style sham;'' CIA mining of Nicaraguan harbors is disclosed; US Congress rejects more contra aid and bans all aid until October 1985. 1985: US imposes trade embargo, gives contras $27 million in humanitarian aid. 1986: US officially gives contras $100 million. Aug. 1987: Ortega and four other Central American leaders sign peace plan in Guatemala. Fall 1987: Under plan, Nicaragua opens dialogue with internal political opposition, declares partial cease-fire, lifts press bans. Jan. 1988: Ortega lifts state of emergency. Sandinistas begin direct talks with contras. Reagan administration seeks $36.25 million in humanitarian and military aid to contras. Feb. 1988: US Congress to vote today on aid request. Nicaragua to continue cease-fire talks.