03/03/08 "The Guardian" -- -- The deaths of Raúl Reyes and Julián Conrado, two senior figures in the Revolutionary Armed Forces of Colombia (Farc), are clearly a serious blow to the guerrilla organisation. It will now call a halt to the release of hostages held by the Farc in the jungle over many years, a process that had been proceeding slowly under the auspices of the Venezuelan president Hugo Chávez. Freedom in the short term for the former presidential candidate Ingrid Betancourt, in which the French president Nicolas Sarkozy has taken a personal interest, now seems unlikely, and many people believe that she is dying. Hopes of the imminent release of three US defence contractors have also been dashed.

By all accounts, the midnight attack on the camp of the Farc leaders, a mile inside Ecuadorean territory in the jungle region south of the Putumayo river, was a political decision taken by the Colombian president, Alvaro Uribe, to end the peace process orchestrated by Chávez. Four Colombian politicians, held as hostages by the Farc for the past six years, were released last week and given a royal welcome in Caracas. Reyes had been among those who organised their freedom. Killed at the age of 59, Reyes had long been more of a diplomat than a guerrilla commander, though he was often photographed in military fatigues and carrying a gun.

According to the Ecuadorean president, Rafael Correa, the bodies of the Farc commanders and 13 guerrillas were recovered in their pyjamas after being bombed while sleeping in a tent on the Ecuadorean side of the frontier. The Colombian air force, Correa claimed, had used advanced technology "with the collaboration of foreign powers" to locate the camp and "to massacre" its occupants. Uribe's government is a close ally of the United States and of Israel, whereas Correa belongs to the radical camp led by Chávez. Subsequent to the bombing, Colombian troops crossed the frontier into Ecuador to recover the bodies.

Ever since 9/11, the United States has requested the Colombian government to refer to the Farc as a "terrorist" organisation, a word also now used by the European Union. Yet the Colombian guerrillas are the most long-lasting of all such movements in Latin America, long pre-dating the current obsession with "terrorism". Their leader, Manuel Marulanda, first led the Farc in the early 1960s and has survived into the 21st century, while Raúl Reyes had run the organisation's political wing for many years. A well-known negotiator and promoter of the Farc's cause in meetings in Europe and Latin America, Reyes was a crucial collaborator in the recent efforts by the Venezuelan president and the Colombian senator, Piedad Córdoba, to release some of the Colombian hostages.

The Farc has witnessed many changes over the past 40 years, but none of them has affected its ability to survive. One change has been the increasing production in Colombia of the raw material for cocaine and heroin, fuelling the drug markets of the United States and Europe, that was once grown in Bolivia and Peru. Land in Colombia devoted to growing cannabis, coca and poppies has grown fivefold since the 1960s, and the Farc has long provided protection to the rural workers on these plantations, as well as exacting tribute from the drug barons.

Another change has been the growth of paramilitary organisations, first sponsored by the drug barons and then by the state, that have revived the pattern of civil war that has been a particular Colombian phenomenon since the 19th century. Coupled with the growth of the paramilitaries has been the US-designed Plan Colombia, a military aid package first agreed with President Clinton in 1999, that has made Colombia the fifth largest recipient of US aid in the world.

A third change has been the collapse of the Soviet Union, and the corresponding loss of influence of the Colombian Communist Party, once the principal political backer of the Farc. The death in 1990 of Jacobo Arenas, the talented Communist leader, left Marulanda and Reyes as the Farc's sole commanders.

Negotiations between the guerrillas and the government have been a feature of the past 25 years, but an unfortunate experience in the 1980s turned the Farc into a reluctant participant. After a ceasefire in 1984, the Farc was encouraged to establish a legal political party, the Patriotic Union, and to put forward candidates in the elections in 1985. The Patriotic Union was reasonably successful, securing six senators, 23 deputies, and several hundred local councillors. But the outcome was disastrous. After emerging into the open and putting their heads above the parapet, many of the UP supporters were singled out and killed. More than 4,000 left-wing activists and organisers were assassinated in the year after the elections. The guerrillas retired to their safe territories in the rural areas, and vowed not to make the same mistake again. Further negotiations took place between 1999 and 2002, but the government negotiators could not overcome this legacy of mistrust on the part of the Farc. When Uribe became president in 2002, he abandoned all such efforts and embarked on seeking an entirely military solution.

Last year, Uribe came under considerable pressure from within Colombia to make greater efforts to secure the release of the hostages, and this was backed by many governments in Latin America as well as by France. Hugo Chávez took up the challenge, and in spite of non-cooperation from Uribe, he was instrumental in moving the process on. The Farc will soon find new commanders, but the wilful slaughter of Reyes and the other guerrillas in an illegal cross-border operation in Ecuador will put all peace negotiations on hold for a considerable time, which was clearly Uribe's purpose in ordering the strike.

He is now getting more than he bargained for. Chávez has indicated his own personal disgust with the Colombian action by closing the Venezuelan embassy in Bogota and by ordering troops to the border. While still dealing with a powerful internal insurgency, Uribe now faces two angry presidents in two important neighbouring countries, mobilising their armies on his frontiers.