The signing of a cease-fire more than two weeks ago with Colombia's last major guerrilla group moves President Belisario Betancur's peace plan, the centerpiece of his domestic program, a long step toward fulfillment.

Both sides, however, express skepticism that the next step, a "national dialogue," will be as successful.

The rebels giving up their arms stressed that the effort to bring them down from the hills could collapse quickly. Betancur's expressed hope is that ending the bloodshed in the countryside would allow farmers and ranchers to return to lands they have abandoned out of fear.

Betancur, a Conservative Party populist, was born into rural northern Colombian poverty and likes to point out that he had no shoes until he went to school. Peace in the countryside could permit the government to devote its scarce resources to solving grave economic problems, and boost the president's prestige.

"It buys the government time, said a wealthy industrialist with close ties to the government. The economy is in a deep recession. The government is battling to control a $2 billion deficit that, while modest by the standards of most other large South American countries, is unusual for Colombia's financial planners.

Businessmen are being asked to pay part of next year's taxes in advance. Unemployment, leading to the poverty that the government recognizes as a major factor in breeding guerrillas, is bound to grow in the short term. The economic future could brighten if newly discovered oil and coal fields begin to produce in two years as planned.

Although conditions are different from those in Central America, a successfully negotiated peace in Colombia could give a boost to the Contadora peace process there. Betancur is a leader of that process.

"Betancur could say, 'Look at my country. Its negotiations were possible,' " said Alvaro Fayad, a sociologist who is a leader of the M19 guerrilla group that signed a cease-fire on Aug. 24.

The guerrillas deny allegations from within the Army that they have accepted the cease-fire to rest and regroup.

"A guerrilla force that doesn't fight, dies," said Fayad. "We can't get stronger during a period of inactivity."

Although the M19 guerrillas acknowledge they are entering unfamiliar territory when they reorganize as a political group, they say they are willing to do so to win at least some changes in the nation's political, economic and social structure. They are also aware that Colombia's guerrillas, some of whom have been fighting governments for close to 40 years, have been spectacularly unsuccessful.

"To our disgrace, we are the oldest guerrilla movement in South America," Fayad said.

But while the rebels have shown they cannot bring down the government, the government must allot considerable resources to control them.

Given this situation of military stalemate, the guerrillas say the government had no choice but to permit a political opening. They say the other alternative, increasing the military repression of the guerrillas, would lead to a new civil war like the one that tore Colombia apart in the 1940s and 1950s.

"If they unleash a wave of repression, it will Central Americanize the Colombian situation and lead to the eventual fall of the oligarchy," said Antonio Navarro Wolff, another M19 leader. "They think they can more easily defeat us politically -- where they have had 170 years' experience -- than militarily."

"We would like the political process to be carried out without the need for arms," said Navarro Wolff, whose guerrillas, under the accord, are allowed to keep their weapons. "If political conditions permit the M19 to turn into a political party, there would be no objection, but if the M19 has to turn into an army, then we can turn into an army. We don't close any option."

The next step is a vaguely defined "national dialogue" that the government has pledged to hold with the guerrillas as well as with other groups traditionally outside a political process dominated by the Liberal and Conservative parties.

"If the national dialogue is frustrated, then guns will again be heard," said an anthropologist who gave her name as Catalina, the only woman in the M19's high command. If war again breaks out, she said, the guerrillas will be in a much stronger position, having achieved a unity that had previously eluded them. They will also benefit from a wave of popular support if the chance of peaceful reform through the national dialogue is blocked, she said.

No one is quite sure what form the national dialogue is to take. Its vagueness has left Betancur open to political attacks, including charges that he has turned the country over to the guerrillas. In a mocking editorial, Liberal ex-president Carlos Lleras Restrepo asked Betancur to explain how it is that his interpretation of the national dialogue coincides with that of the guerrilla groups.

Apparently it does not. According to the chairman of the govenment-appointed Peace Commission, John Agudelo Rios, the national dialogue will be conducted through 10 round tables that will study different social problems.

"It is a mechanism convoked to find out the opinions of the great number of Colombians who had previously expressed no opinion because they lived outside the democratic political process," he said.

An M19 statement defined it differently: "The national dialogue is not a committee nor long speeches behind closed doors, nor weighty volumes about the problems of the country." Rather, it said, for the M19 and other guerrilla groups, the dialogue is a massive mobilization of the close to 55 percent of Colombia's 16 million eligible voters who did not vote in the last presidential elections through demonstrations, strikes and other political acts with the aim of forcing through major changes.

To begin the process of political mobilization, M19 detailed part of its leadership -- those among the close to 2,000 guerrillas who took advantage of an amnesty proclaimed by the government in November 1982 -- to Colombia's cities.

Just before the cease-fire was signed, one of those, Carlos Toledo Plata, an M19 founder and ideologue, was gunned down in front of his home in Bucaramanga. Toledo Plata, an orthopedist, planned to open a clinic with a government loan made available under the amnesty program. His death postponed the cease-fire by 10 days and was the reason given by the guerrillas for an attack on the industrial city of Yumbo that left at least 42 persons dead.

More assasinations could spell the end for the cease-fire.

"Very probably, they will kill some of us," said Catalina, who is in Bogota for the national dialogue. "We entered the process knowing it was dangerous."

Skeptical of the guerrillas' motives, Colombia's military has nevertheless pledged to uphold the cease-fire.

"For a long time the military has asked for a political treatment of the problem," said a top general. "We are determined to carry out the attempt at a political solution to its final consequences. There is no opposition to that."

While armed clashes with the guerrillas have fallen sharply since the truce, kidnapings have risen, the general said. Perhaps the guerrillas' most important method of financing, kidnaping has taken on the dimensions of a national industry and it is difficult to determine whether guerrillas or common criminals are responsible for any particular crime.

However, Army intelligence charged that several guerrilla groups that have signed the cease-fire are continuing their kidnaping operations. Extortion based on the threat of kidnaping is also on the increase.

"While these signs persist, one cannot be realistically optimistic on the prospects for peace," the general said.

Many officers say the cease-fire enabled guerrillas who were bottled up in rural areas to enter the cities that they were unable to take militarily.

"They will now use political channels to accelerate the revolutionary process," the general said.

"The hope is that the government's peace policy will be successful. But if it is not successful, then the situation will be very difficult," he said, adding that a military solution would require mobilization of the country and would push it to the brink of civil war.

"The armed forces are the party most interested in peace," he said. "My sons are lieutenants. How can we pray for war?"