BOGOTA (Reuters) - The killing of Colombia's top guerrilla boss will quiet criticism of President Juan Manuel Santos, whose popularity has taken a hit over perceptions the Andean nation's security gains were being reversed.
In one of the largest strikes against the guerrillas, Colombian forces killed FARC leader Alfonso Cano Friday. But the insurgents vowed to fight on, dampening hopes that Cano's death might bring the nation closer to peace.
Latin America's No. 4 oil producer has pummelled leftist rebels since launching a U.S.-funded military crackdown in 2002, drawing in billions of dollars in foreign investment. But ambushes, bombings and combat still happen regularly.
Santos -- who came to power last year vowing to keep up the hardline stance against rebels of his predecessor Alvaro Uribe -- has seen his popularity in opinion polls drop this year, driven by the belief that insecurity was rising once again.
"The killing of Cano will give Santos a massive boost. For a good time it will end the debate about a deterioration in the security situation," said Christian Voelkel, an analyst with the International Crisis Group think tank.
The scion of a wealthy Bogota family, Santos has been at the helm of some of the biggest blows to FARC rebels in their history, first as defence minister and then as president.
He also took flak, however, for allegations of abuses by the army when he was Uribe's defence minister that included massacres of innocent peasants.
Despite a drop in polls, Santos still has mouth-watering approval ratings for any politician, hovering around 67 percent. But worries on the security front saw a change in the defence minister and military top command early this year, along with a vow by the president to redesign security policy.
"It renews confidence for the moment but it's not a guarantee that security will get better," independent security analyst Alfredo Rangel said.
"It doesn't solve the underlying problems behind the deterioration in security. This improvement may only last a relatively short time."
The demise of Cano may silence one of the Colombian leader's most-powerful critics, Uribe -- whose popularity and support helped Santos get elected in 2010 but who has increasingly come out against him since then.
The way the government has handled the death of Cano also speaks to deep differences in style between the two administrations; Santos has dealt with it in a less emotive way than Uribe would have, experts said.
That may also play out in the coming months with Colombia's regional ties, since computer files and USB drives recovered from Cano may -- like previous ones from the death of former FARC leader Raul Reyes in 2008 -- bring up uncomfortable questions about neighboring countries' role in the conflict.
The cross-border attack that killed Reyes in Ecuador triggered a diplomatic dispute among Uribe and counterparts in both Quito and Caracas, which escalated when Uribe accused Venezuela of harbouring and supporting the drug-funded rebels.
"No one wants to have a rerun of the mishandling of the Raul Reyes files. Santos will be very careful," Voelkel said.
"Santos is more capable of handling sensitive information and possible allegations that might come up than Uribe."
The Cano killing came days after Santos allies did well in nationwide regional elections, underlining his support among the vast majority of Colombia's political parties.
However, despite dominating the political landscape, the difficulties of convincing a coalition of disparate parties will make it hard for him to push through much-needed reforms, including to the tax system and agriculture.
And in Colombia's rural areas, continued violence by the FARC, other rebel groups and heavily armed criminal gangs remains a huge challenge, as does dealing with one of the world's largest internal refugee populations.
Additional reporting by Luis Jaime Acosta; Editing by Andrew Cawthorne and Cynthia Osterman