On Thursday, the former chief negotiator for the Revolutionary Armed Forces of Colombia announced he would resume fighting, alleging the government has failed to uphold the 2016 peace accord and accusing it of standing by as hundreds of social leaders have been slain in rural areas where the rebels long dominated.
Almost immediately, President Iván Duque reached out to Venezuelan opposition leader Juan Guaidó, whose nine-month campaign to unseat Maduro has stalled amid the refusal of Venezuela's military to abandon the embattled leader. For both men, the video was further proof that the rebels, which are designated a terrorist group by the U.S., are plotting attacks from Venezuelan soil.
"We're not witnessing the birth of a new guerrilla army, but rather the criminal threats of a band of narco-terrorists who have the protection and support of Nicolás Maduro's dictatorship," Duque said in a televised address.
Added Guaidó: "All Venezuelans should reject these types of threats that undermine our sovereignty."
Venezuela's Foreign Minister Jorge Arreaza angrily rejected the accusations on Friday, turning instead on Duque, whose intransigence he blamed for leading the rebels to abandon the peace process.
"His attitude not only puts at risk the normalization of life in Colombia but also threatens the peace and security of South America," Arreaza said.
Nonetheless Duque's concerns were echoed in Washington, where U.S. officials reiterated accusations that Maduro's government has been actively conspiring with Colombian rebels, especially the more radical National Liberation Army, or ELN, which is believed to fund its insurgency by smuggling cocaine and gold through Venezuela.
"The regime in Caracas seems to be fomenting this kind of activity, in essence turning over parts of the country, particularly to the ELN," Elliott Abrams, the Trump administration's special envoy to Venezuela, told reporters.
Colombian authorities, so far with little evidence, have long asserted that Marín has been hiding out in Venezuela along with other top rebel commanders from the ELN and a group of dissident FARC rebels that never handed over their weapons.
In recent months, at least three meetings are believed to have taken place among the rebel commanders converging by small planes on the small Venezuelan town of El Nula, a lawless area heavily patrolled by Venezuela's military 30 kilometers (about 20 miles) from the border, said a Colombian military intelligence official, who insisted on speaking anonymously because he wasn't authorized to reveal the intelligence assessment.
The same official asserted that ELN rebels were present when Russian military instructors earlier this year trained members of Venezuela's armed forces in military doctrine and the use of explosives, although not necessarily with the foreigners' knowledge. The Associated Press was unable to verify the official's claims.
Overall, authorities estimate as many as 1,000 ELN rebels — or around 40% of the group's fighting force — operate from Venezuela, where they plan attacks like the January car bombing at a Bogota police academy that killed more than 20 mostly young cadets.
Maduro and his allies have long denied they are providing material support to Colombian rebels, and portray the U.S. claims part of a Western media-hyped campaign to pave the way for an invasion.
A decade-long, U.S.-funded military buildup in Colombia forced the FARC to the negotiating table in 2012. Intelligence officials have long maintained that the rebels are unable to concentrate in large numbers inside Colombia for fear of being killed like a string of previous FARC commanders who were taken out in airstrikes using U.S.-provided intelligence and smart bombs.
As if to underscore that point, authorities announced Friday that nine guerrillas belonging to a FARC faction that never demobilized were killed in an aerial raid. Few details of the operation were released, but Duque said the dead included a rebel known by his alias, Gildardo Cucho, who was among those Marín was looking to recruit to his new guerrilla movement.
"We're putting the criminals on notice: either they surrender or they will be vanquished," Defense Minister Guillermo Botero said on Twitter.
That leaves socialist-ruled Venezuela, whose ideological affinity with the rebels is well known.
While Maduro played a key role in brokering the 2016 peace accord, he has increasingly flouted calls to banish the rebels as tensions with the U.S. and his neighbors have mounted. Last month, he even went so far as to announce that Marin and a close ally, Seuxis Hernández, wanted by the U.S. on drug charges, would be "welcome in Venezuela" as "leaders of peace." Hernandez, better known by his alias Jesús Santrich, was seen in Thursday's video standing next to Marín holding an assault rifle.
Since the outset of Venezuela's crisis, when Guaidó in January declared himself interim president and quickly won recognition from dozens of foreign governments, the U.S. has been leaning on allied Colombia to lead the campaign against Maduro. But while U.S. officials have repeatedly floated a military option to remove Maduro, Duque has steadfastly rejected the idea, fearing it could get Colombia mired in a prolonged conflict that would have scant regional support.
"Things can get ugly fast and there's no way for the Colombians to know how a military intervention will end," said Michael Shifter, president of the Inter-American Dialogue in Washington.
Nonetheless, hardliners seized on the news of the rebels' rearming to push for a more forceful international action against Maduro — although nobody openly called for a foreign military intervention.
"For the Maduro regime and its criminal allies, the priority right now is destabilizing Colombia," said María Corina Machado, a government opponent who was stripped of her seat in Venezuela's congress.
Venezuela also appeared prominent in the minds of the deserting rebels, with Marín in his video angrily rejecting the "absurd idea of being lackeys of Washington in an unjust war" to oust Maduro.
While few in Colombia expect a rearmed FARC faction to immediately regain military leverage, their return to the battlefield, and a potential alliance with ELN and other dissident rebels, represents a major spillover risk for the fast-escalating crisis in Venezuela.
"The worst thing for Colombians and Venezuelans is that the two countries' disputes, which have very different origins, fuse into a single conflict," said Vladimir Villegas, a prominent Venezuelan journalist who used to serve as Venezuela's deputy foreign minister. "The Venezuelan government and armed forces need to guarantee we are a territory free of irregular armies, no matter what their banner. If they don't, the conflagration will be far worse than the fires burning in Amazon."
Joshua Goodman on Twitter: https://twitter.com/APjoshgoodman