Nobody ever said bringing peace to this once-chaotic country, where the threat from drug-fueled rebel groups led to sharply expanded U.S. military aid, would ever be easy.

But little by little and amid angry recriminations in a politically polarized landscape, Colombia’s government and the Revolutionary Armed Forces of Colombia, a once-potent communist guerrilla group also known as the FARC, have been advancing in peace talks in Cuba to end Latin America’s last guerrilla conflict.

Back-channel communications have also begun with a smaller rebel group, the National Liberation Army, or ELN, which may lead to official peace negotiations in months, said Aldo Civico, a Rutgers University expert on the ELN who has spoken to people involved in the discussions.

“I do think it’s going to happen,” said Francisco Galan, a former ELN commander. “I think the stars are aligned.”

Both the ELN and the FARC are down to about 12,000 armed fighters. That is substantially weaker than before the start of a decade-long government offensive, which relied on billions of dollars in U.S. military equipment and intelligence that helped Colombia’s security forces kill top rebel commanders and triggered mass desertions.

And the nine months of official talks between President Juan Manuel Santos’s government and the FARC have advanced further than any of the three previous negotiations that Colombian governments had held with the rebels.

But there are crises.

On Friday, the FARC said it would “pause” negotiations after criticizing Santos for having presented a bill to Congress that would permit a referendum for Colombians to vote on any peace accords. Hours later, the group said it would return to talks Monday.

But Santos still ordered half of his negotiating team back to Bogota for consultations, saying, “In this process, the one who declares pauses and puts conditions is not the FARC.”

Although government officials said the entire team would be back in Havana on Monday to resume talks, such squabbles have given ammunition to opponents of the talks and soured millions of Colombians on the possibility that peace will ever come to this country of 47 million people. On Saturday, news that a guerrilla ambush in the country’s eastern plains had killed 13 soldiers further outraged Colombians.

A poll published in July showed that 54 percent of Colombians surveyed were pessimistic about the talks, up from 41 percent in September 2012.

“I think there is a repudiation of the whole notion that people in the FARC should be treated other than war criminals,” said Cynthia Arnson, an expert on Latin American peace processes at Washington’s Woodrow Wilson International Center for Scholars.

Critics of the talks, meanwhile, include powerful figures capable of influencing the public, among them former Colombian president Álvaro Uribe. He argues that the talks pose a threat to democracy by opening the door for political participation to a group of terrorists.

“The only thing that is clear is they want to take us to Castro-Chavismo,” Uribe said Friday, referring to the radical and authoritarian governments of Cuba and its ally Venezuela, whose late president, Hugo Chavez, had assisted the FARC.

Although the FARC and the government reached agreement on the nettlesome issue of land reform in May, they still have four major points to decide in the agenda for talks, including how to battle drug trafficking in rural areas and create a verification process for the disarmament of rebel forces.

Now they are negotiating how to transition rebel commanders into politics, discussions that the government’s peace commissioner, Sergio Jaramillo, compared to a roller coaster ride. “Things often stall and then suddenly something clicks and you start moving quickly,” he said. “We are at that point.”

But the clock is ticking: Congressional elections are scheduled for March, and many opponents of the peace process are expected to be swept into office.

“Most sensible candidates will want to get elected on a peace ticket and will therefore want to implement the agreements,” Jaramillo said of a future peace accord. “That’s what the FARC need to understand.”

Then the presidential election comes in May, and Santos is expected to face adversaries who accuse him of being soft on the guerrillas.

People close to the negotiations say the FARC’s commanders, who hope to form a political party after the end of hostilities, are clear that it would be in their interest to reach an accord well before the elections.

“They themselves know that time is against them and that the wearing down of the government won’t benefit them,” said Enrique Santos, who is the president’s brother and served as an emissary to the FARC. “These factors are leading them to be more pragmatic.”

Indeed, on Tuesday one of the group’s commanders, Jorge Torres Victoria, better known by the alias Pablo Catatumbo, read a statement in Havana in which the group for the first time accepted partial responsibility for a conflict that has left 220,000 people dead over half a century.

“Without a doubt, there has also been cruelty and pain provoked by our forces,” he said.

The two sides are expected to soon begin negotiating how to respond to victims of the conflict while ensuring that there is justice for war crimes.

Next week, the country’s Constitutional Court rules on whether a legal framework set up to address the violence is legal. The framework, which would amend the constitution, has triggered criticism from human rights groups that say it would disregard victims’ rights and ensure impunity.

“It’s second-class kind of justice,” said Gustavo Gallon, director of the Colombian Commission of Jurists, a rights group based in Bogota. “We’re talking of crimes such as homicides, assassinations, massacres, rapes, forced displacements of villagers.”

A highly regarded study of the violence recently found that the FARC is responsible for 576 attacks on towns in the last quarter century and 12,790 kidnappings from 1970 to 2010. The study by the state-supported group, the National Center for Historic Memory, also found that the FARC had killed 3,261 people between 1981 and 2012, nearly a third of them in massacres.

Still, FARC commanders say they do not expect to spend a day in jail.

Among those battering the government over the talks is the president’s cousin, Francisco Santos, a candidate for president in Uribe’s rightist movement.

“We agree about peace, but not a peace that gives legitimacy to a group that has done nothing but kill Colombians,” Santos said in a debate this week with other presidential hopefuls.