Colombian officials and leftist FARC rebels returned to the bargaining table in Cuba in the past week, with both sides saying their two-year-old peace negotiations were on a stronger footing after having survived their first major crisis.

The conversations were frozen Nov. 16 by President Juan Manuel Santos after the guerrillas captured Brig. Gen. Rubén Alzate, the highest-ranking military official ever to fall into rebel hands.

FARC commanders initially signaled that they would use Alzate as a bargaining chip, but the general and four other captives were soon freed in what the guerrillas said was a “humanitarian gesture” affirming their commitment to ending the 50-year-old conflict, which has cost 220,000 lives.

On Friday, U.S. Secretary of State John F. Kerry expressed “full support” for the negotiations in an appearance with Santos in Bogota, while also urging a quicker pace to the talks.

“The longer it takes, the harder it will be,” he said.

Colombia analysts and sources close to the negotiations say that the Alzate episode has served as a stress test of sorts, allowing Santos to show that he remains in the driver’s seat while letting the FARC rebels take the high road to try to rehabilitate their dismal public image.

“One of the Colombian public’s biggest doubts about the process was whether the FARC are serious about seeking peace,” said Adam Isacson, a security analyst and Colombia expert at the Washington Office on Latin America.

“Well, the FARC — a group known for holding military officers hostage for 10 years — was just forced to choose between holding their highest-ranking captive ever or keeping the peace talks going. They chose peace. That’s a pretty big deal,” he said.

Alzate and two colleagues were seized along a jungle river in a region of western Colombia known for rebel activity. The general was traveling without a security escort, in civilian clothing and said later that he had planned to visit a community development project as part of a counter-insurgency effort.

FARC rebels took Alzate without firing a shot, but the group’s leaders soon came under significant pressure to swiftly release the general, according to negotiators — especially from Cuba, which is hosting the peace talks.

Two weeks after his capture, Alzate was freed and promptly resigned.

The episode came at a crucial juncture in the peace process. After two years, FARC commanders and government negotiators have reached agreements on the lower-hanging elements of their five-point agenda, such as the promotion of rural development, the elimination of the illegal drug trade and guaranteeing that FARC members will eventually be able to participate in electoral politics.

By design, none of those agenda items can be implemented until the entire peace deal has been finalized. And the stickiest elements remain unresolved.

They include issues of justice and reparations for victims of the conflict, as well as the handover of weapons and the demobilization of the FARC’s 8,000 or so combatants. Most sensitive of all is the matter of appropriate punishment for rebel commanders, many of whom have multiple convictions for murder, drug trafficking and other major crimes.

As many as 50 FARC leaders are thought to be facing orders for their extradition to the United States, including several of the commanders sitting at the bargaining table in Havana.

“The negotiations are at a phase in which the FARC is facing transcendental decisions,” said María Victoria Llorente, director of Colombia’s Ideas for Peace Foundation in Bogota.

The peace process has included several rounds of emotional testimony from victims of the conflict on all sides, and Llorente said their participation has helped win legitimacy for the talks in the eyes of the Colombian public.

“Taking victims to Havana has been key in bringing some perspective to the process and making FARC show a bit of humility, which is something that Colombians have been clamoring for,” she said.

The contrition of rebel leaders — or the perceived lack of it — may be as important to the peace process as any of the agenda items. In that regard, the guerrillas can be their own worst enemies, often casting themselves as victims of government aggression.

With every passing month, the negotiations seem to morph more into a three-way chess match between the rebels, the Santos government and powerful former president Álvaro Uribe, the voice of skeptical Colombians who don’t want to see FARC get a free pass.

Even as the government and the guerrillas battle in Colombia’s jungles, it is becoming clear that the Santos administration and the FARC will need one another to help sell their peace effort to the public.

Santos needs the rebels to show remorse but also to accept some form of punishment that will help make any eventual deal palatable to a majority of Colombians, who will vote on whatever agreement emerges from the secret talks.

If the voters reject an agreement, the whole effort would have been for naught.

Government negotiators are pushing the rebels to move faster, knowing that the Colombian public is losing patience and that dallying by FARC is viewed as disrespectful and self-indulgent.

Such delays play into the hands of FARC archenemy Uribe, whose poll numbers are considerably higher than those of his political rival, Santos. Uribe is widely expected to lead the campaign against any peace deal deemed too soft on the rebels.

As talks resumed in the past week, Uribe accused the Santos government of granting secret concessions to the FARC. Government negotiators vehemently denied those claims.

“It’s really unfathomable that a former president can simply make things up like that,” Sergio Jaramillo said in an interview. Jaramillo, Colombia’s high commissioner for peace and the lead architect of the process, called the allegations “a total fabrication.”

Jaramillo said that his side has emphasized to the rebels that the clock is ticking and that it ticks for all. “Time is our common enemy,” he said.