His country is beset by economic recession, natural catastrophes and bands of leftist terrorists. His public support has shrunk to an all-time low and there is public speculation about the possibility of a military coup.

So earlier this month, Fernando Belaunde Terry, the tireless idealist of a Peruvian president, set off on a river trip in the jungle.

For four days, while Peruvians debated the renegotiation of their foreign debt and endured insurgents who bombed the lights out of the capital, their 69-year-old president motored down the farthest reaches of the Amazon and Orinoco river networks, demonstrating his vision of integrating South America's waterways.

For all its strangeness, it was a gesture with a certain logic. This is the drizzly mid-winter of a country dogged by disasters, and offering dreams, people here say, seems to be the most anyone can do.

Peru is suffering one of the worst years in its modern history--so bad, violent and unlucky that even many of the nation's leaders appear close to despair.

"We have been left stranded in the river in a precarious balance," said a close associate of Belaunde. "The current is getting stronger, and we are getting weaker."

Like most South American countries, Peru is mired in recession and burdened with foreign debt it cannot pay. But that is only the beginning. An unprecedented combination of floods and drought has wiped out much of the country's food supply, left thousands homeless and forced an international emergency program to prevent starvation.

National economic production dropped a stunning 10.9 percent in the first three months of this year compared with 1982, and inflation is running at 110 percent. Tourism, an economic staple, has dropped by more than 50 percent in two years. Meanwhile, the enigmatic Maoist insurgent group, Sendero Luminoso (Shining Path), has provoked the declaration of a national state of emergency with a guerrilla war in the southern Andes and mounting terrorism in the capital.

"People have been suffering here for a long time, and the suffering is reaching a breaking point," said Manuel Ulloa, a senator and former chief Cabinet minister in Belaunde's government. "There is a tendency to be pessimistic and to look at everything with a jaundiced eye."

Many Peruvians say that neither Belaunde nor Peru's three-year-old democracy can be blamed for all the trouble. Yet, businessmen, politicians, and workers say they have all but lost hope for broad solutions. "We have tried everything," said a businessman who has sold his plant. "Now we know there are no easy answers here."

Peruvian politicians and prominent progovernment news media have been speculating for months about the chances that Belaunde, ousted as president in 1968, might again be overturned by a military coup. Yet, with a certain irony, diplomats and sources close to the military say that the very depth of the crisis seems to have helped democracy by discouraging potentially conspiratorial officers.

"There is a great difference between the situation of 1968 and now," said retired Gen. Edgardo Mercado Jarrin, a top leader of the leftist administration that reigned for more than half of the 12-year military rule. "Then the armed forces offered a complete national project for the country. Now, the armed forces are not in a position to offer a comprehensive solution to the nation's problems. There will be no coup, only a slow worsening of the crisis."

This kind of depressed outlook springs in part from years of political and economic failure. Although rich in resources and native Indian culture, Peru has long been unable to support the needs of a population that now stands at more than 18 million. Three years ago, the World Bank estimated that 49 percent of Peruvians earned an income below the poverty level.

The country revolved between military and civilian governments for decades before idealistic Army leaders took power in 1968, promising to transform the nation with socialism. By almost all accounts, they failed. Between 1974 and 1982, real incomes in Peru dropped by 40 percent.

Belaunde, a relatively conservative populist, took office for a five-year term in July 1980 promising to liberalize and reactivate the statist economy created by the military.

"Something has been done, but it's less than needs to be done," said Ulloa, the former economy minister. "We haven't had any real growth to speak of for 10 to 15 years."

"As much as can be expected, we're coping with the situation," added Ulloa, who is expected to be a candidate for the 1985 presidential nomination of Belaunde's Popular Action party. "But it's difficult because people are not really prepared."

While Peru was afflicted by a flat growth rate and problems with its $11.5 billion foreign debt last year, it is the more recent natural disasters that have created the most serious problems.

Skewed by the irregular pattern of the nearby El Nino current in the Pacific Ocean, weather has wreaked havoc on Peru's northern and southernmost departments. Six months of heavy rains and flooding wiped out crops, bridges and roads and left more than 130 persons dead in five northern departments, and a drought destroyed the only yearly crop of most of the poor farmers in southern Peru.

Government officials estimate that $884 million in damage was done by the irregular weather and that 5 percent of Peru's economic product of last year was lost. Diplomatic reports estimate the loss of 11 percent of the agricultural and livestock production, including 34 percent of beef supplies, 23 percent of corn, 27 percent of potatoes and 20 percent of rice.

Despite a large government emergency program and international aid--including $25 million in special food grants and loans from the United States--government officials and relief experts say there is still a danger of deaths through starvation. Although the floods and drought ended in June, 620,000 people in three southern departments--out of about 1.1 million--are estimated to be "severely affected" by the drought and food shortages.

As in its fight against leftist insurgents in the south-central mountains, the government has lacked the basic resources to fully handle the problem. In both north and south, supplies and repairs are often slow to arrive and activists recently organized a general strike in the south to protest what they charged was inadequate government action.

While the Shining Path movement now offers no serious military threat to the government, the psychological impact of its bombings in a year of crisis has been strong.

"It's when everything else is bad that turning the lights out counts," a diplomat said. "People tend to think that no one's in control."

For many politicians and analysts, the crisis has only been worsened by some of the policies of Peru's still-maturing political movements. Belaunde has been criticized for launching unsubstantiated attacks on the Roman Catholic Church, the foreign press and foreign-financed foundations, for allegedly helping the leftist insurgents or participating in an international campaign against Peru.

Many opposition leaders, meanwhile, have rejected government efforts to reach a consensus on such issues as the foreign debt and political violence, apparently hoping to capitalize on the crisis in municipal elections scheduled for November.

"There is a real lack of political maturity," said Luis Bedoya, the president of the Popular Christian Party. "Because of the freeze of military rule, people started in politics here in 1980 with the ideas of 1968. They haven't learned anything or forgotten anything. They are just caught in time."

Some diplomats and other independent observers believe that Peru already may have survived the worst of its problems. With the coming elections, political tensions will be channeled into a democratic path, they predict, and the incipient economic recovery in the United States will help push Peru out of recession.

Work already has begun on rebuilding bridges and roads destroyed by floods, and some economists predict that the disaster zones of this year will suddenly turn dynamic with the influx of reconstruction funds and jobs.

Long-suffering Peruvians can only hope they are right. For now, a diplomat said, "people tend to have the feeling that something has to happen to take the pressure off."