Leading article: The end of this war is still not in sight

This week's rescue of Colombia's former presidential candidate Ingrid Betancourt and 14 other hostages was not merely an operation executed with quite sensational skill. It is also the latest of several major blows that may just hasten the demise of the Marxist guerrilla group FARC, which has blighted the country's politics for more than four decades.

The rescue, in which not a shot was fired, is a humiliation for FARC (the Revolutionary Armed Forces of Colombia), and vindicates the hard line pursued by President Alvaro Uribe. The infiltration which made it possible only underscores the disarray and vulnerability of the group after the death of its founder and legendary commander Manuel Marulanda earlier this year, and the killing of two high-ranking military leaders.

Most important, the freeing of Ms Betancourt has removed FARC's biggest bargaining chip to extract the concessions it has long sought – a prisoner exchange involving the release by the government of captured FARC rebels in return for the hundreds of hostages held by the group, and creation of a demilitarised safe haven for the group in the south of the country.

Increasingly, FARC's existence is a self-perpetuating futility. Its fighting force, now perhaps only 8,000, is half or less what it was in the group's heyday. It enjoys the sympathy of 5 per cent at most of Colombia's population, and derives more of its dwindling power from control of the drugs trade in its remote strongholds than from any ideological appeal to the masses. Its main international supporter of note is Venezuela's demagogic Hugo Chavez. Worst of all from its point of view, the Betancourt rescue testifies to a new professionalism on the part of the Colombian army that can only bode ill for FARC's military prospects.

In essence, the group – sometimes described as a cocaine cartel in Communist clothes – faces a simple choice. The first, and best, option would be to accept the offer of negotiations renewed by the Uribe government after the rescue. This would facilitate a humanitarian exchange of prisoners, and ideally lead to a peace agreement whereby the FARC laid down its arms in return for immunity and turned itself into a left-wing party operating within Colombia's orthodox electoral process.

But the omens are not promising. The group has spurned or stonewalled such offers in the past, most notably between 1998 and 2002, when the government of the former President Andres Pastrana gave it a demilitarised zone as a carrot to start negotiations. The likelihood remains that FARC will continue a struggle it has no chance of winning – but can probably sustain for some time, thanks to its drug and kidnapping revenues and its local grip on power.