The helicopter headed west, rotors scything the air, towards the border with Colombia and a setting sun. The jungle canopy below was so thick that even at treetop level it was impossible to see what, or who, might be on the ground.
The Venezuelan Mil Mi-35 combat transport helicopter was like a steel sauna and when it touched down in a clearing the crew quickly opened the doors. It made no difference. The air outside was hot and sticky. While other helicopters flew overhead, soldiers from the 12th Infantry Brigade fanned out into the trees, assault rifles at the ready, to reclaim a patch of Venezuela.
The frontier with Colombia, a red line on military maps, was just a few yards away but the jungle made no distinction - and nor did the guerrillas and armed groups which roved this no man's land near Boca de Grita in Zulia state, on the 1,400-mile border.
A Venezuelan patrol had discovered a secret training camp with weapons, huts and tunnels and General Jesús González, head of strategic operations, had come to oversee its destruction. 'We've found uniforms, night-vision equipment, stashes of drugs, the lot,' he said, tramping over debris. Moments later there was a loud explosion and a spiral of grey smoke; army sappers were blowing up the rest of the camp. 'Very good,' said the general. He lit a cigar and grinned.
This South American jungle is rife with snakes, mosquitoes and disease but for four decades it has sheltered the Revolutionary Armed Forces of Colombia (Farc), guerrillas battling the Colombian state in South America's longest-running conflict. It has seemed endless, a saga of brutality and suffering seeping from one generation to the next. Last week, however, something happened which may hasten its end.
Venezuela's President, Hugo Chávez, a self-styled socialist revolutionary revered as an icon and ideological soulmate by the rebels, announced that the game was up. 'At this point in Latin America, an armed guerrilla movement is out of place. Guerrilla wars are history. Enough of all this war. The time has come to sit down and talk peace,' he said.
It was an astonishing u-turn made all the more dramatic for being broadcast live on TV and radio and addressed directly to the rebels, who are known to avidly follow Chávez's speeches on transistor radios. He stopped short of demanding their surrender but urged unilateral concessions such as the freeing of hostages the Farc have held in mountain camps for years. 'I think the time has come for the Farc to free everyone they have in the mountains. It would be a great humanitarian gesture in exchange for nothing,' he said.
The effect on Farc morale was expected to be devastating. Colombia, which has accused Chávez of funding and arming the rebels - a claim he denies - welcomed the statement. So did Washington: the Bush administration's first kind words about its Venezuelan bête noire in a long time.
Analysts said Chávez distanced himself from the guerrillas for several reasons - of which the most important was probably that Farc is losing. In recent months it has suffered one blow after another, leaving the organisation punch-drunk and possibly mortally wounded.
'It is hard to overstate the setbacks,' said Michael Shifter, of the Inter-American Dialogue think-tank. 'No expert believes the Farc still pose a strategic threat to the state. If Chávez follows through and matches actions with rhetoric, that will have huge implications.'
The helicopter mission to the border to blow up the clandestine camp was not proof of such a crackdown. The guerrillas are believed to have several bases inside Venezuela but the one destroyed near Boca de Grita was more likely used by right-wing paramilitary narco-traffickers. Nevertheless, it showed Venezuela's military stepping up efforts against drug trafficking, the Farc's main income source.
After almost half a century of violence the Marxist group is widely considered an anachronism destined to follow Latin America's other guerrilla groups into oblivion. The Farc was born out of a civil war which had consumed more than 200,000 lives by 1958. When the army pursued left-wing survivors and peasants in the Andean mountains south of Bogotá in the 1960s they struck back.
At its height in the late 1990s the Farc boasted 19,000 fighters and controlled cities. The Berlin Wall had fallen, Marxism was discredited and rebels in other countries had been defeated or joined mainstream politics. But the Farc fought on. Pro-government death squads murdered its political activists and there was another compelling incentive to remain outlaws - cocaine.
Booming demand in Europe and the US meant billions of dollars in revenue for the guerrillas, gangsters and right-wing militias who harvested the coca leaf. It was lucrative but eroded the Farc's legitimacy at home and abroad. From 2002 the military tide also began to turn. President Alvaro Uribe used US military aid to turn Colombia's police and army into formidable counter-insurgency forces.
The guerrillas retreated deeper into jungle redoubts bordering Venezuela and Ecuador, taking an estimated 700 hostages with them, but now those sanctuaries are no longer safe.
Since its foundation the Farc's seven-man ruling secretariat had been untouchable. In March it lost three members, the worst month in the guerrillas' history. Colombia's military killed Raúl Reyes in a raid into Ecuador which netted laptops and an intelligence trove. A Farc bodyguard killed Ivan Rios for a reward. And the group's leader and founder, Manuel Marulanda, died of a reported heart attack aged 78.
A female commander, Nelly Avila Moreno, better known as 'Karina', surrendered soon after and declared that the Farc was crumbling. Many units were encircled and isolated, she said.
Nearly 300 guerrillas are deserting every month, according to a government programme to 'reinsert' members into civilian life. Some 2,480 Farc members deserted in 2007, more than double the number for 2005. The haemorrhaging follows a government campaign offering ex-combatants education, training and rewards for information about arms stashes and commanders. 'Guerrilla, demobilise,' say the adverts. 'Colombia and your family are waiting for you.'
Carlos, a veteran Farc fighter, told The Observer he recently quit as a bodyguard for a commander because the pressure had become too much. 'The army is pushing deeper and deeper into our territory. There are frequent bombing raids from the air force. They never hit our camp, but they got close a couple of times. We never had any trouble getting food, but it's become harder to get other supplies, like ammunition. The biggest problem is the lack of medicine,' he said. Many of his comrades deserted, but rather than hand themselves in many ran away and sought work on farms.
Admiral David Rene Moreno, second-in-command of Colombia's armed forces, believes the conflict could end within five years. He said: 'The Farc are now so weak that they'll have to negotiate peace with the government very soon. Just today, for example, another 18 handed themselves in.'
Adam Isacson, a Colombia analyst for the Washington-based Centre for International Policy, warned of a messier, prolonged outcome. 'The most likely scenario - though it's not a sure thing by any means - is that there will be some kind of fragmentation,' he explained. Militarists who want to fight on could clash with those favouring a political settlement and the 'narco' faction could split with those opposed to drug trafficking.
'Maybe in 10 years the government could win militarily. But even the ELN, a smaller guerrilla group, which is probably down to about 1,000 members, is not even responding to the government's overtures now. So why should the Farc - with as many as 12 times more people - be anywhere near that kind of defeat? I think that militarily it's going to be a long slog, a real war of attrition for a very long time.'
Brothers in arms: Latin America's revolutionaries
The Sandinistas
Darlings of the international left after overthrowing the Somoza dynasty in 1979, the Marxist guerrilla group went on to govern Nicaragua for 11 years. They took their name from Augusto Sandino, a nationalist rebel assassinated in 1934. Regained power in the 2006 elections after 15 years in the wilderness.
The 26 July Movement
Led by Fidel Castro and Ernesto 'Che' Guevara, the 26 July Movement swept to power in Cuba in 1959, ousting the Batista regime and established a communist regime in the backyard of the United States.
Shining Path
Peruvian Maoist group formed by former philosophy lecturer Abimael Guzman in the early 1970s. Widely condemned for the brutality of a series of terrorist attacks beginning in the 1980s. Only sporadically active since the capture of Guzman in 1992.
The October Revolutionaries
Launched Guatemala's '10 years of spring' in 1944 after overthrowing the military junta and instituting liberal reform. Made up of a coalition of students, professionals and workers. Toppled by a coup d'etat in 1954.
