Squinting into the glare of the late-afternoon Caribbean sun, hundreds of pleated khaki-dressed soldiers and military dignitaries form orderly rows facing their chief of staff and head of state, Venezuelan president Hugo Chávez.

Positioned on stage and flanked by a few lines of tanks and helicopters in a military training ground in the provincial city of Valencia, western Venezuela, President Chávez waits for the roaring fighter jets to pass overhead before addressing the assembly.

"From Colombia, Venezuela is threatened," Chávez says, dismissing as "inventions" widespread allegations that his government has colluded with drug trafficking and arms sales to Colombian guerrillas.

The speech is being delivered to mark the 16th anniversary of the attempted coup led by the then-young Lieutenant Colonel Chávez on 4 February 1992. Although it ended in failure and Chávez and his cohorts were imprisoned, many believe the event - now commonly referred to as 4F - paved the way for his eventual democratic election to the presidency in 1998.

But while the Venezuelan president was commemorating his failed putsch, over a million protesters took to the streets in neighbouring Colombia and in cities across the world to voice their opposition to Chávez's hostage-taking rebel allies, the Revolutionary Armed Forces of Colombia (Farc).

In an almost implausible coincidence, anti-Farc campaigners chose 4 February to mobilise a global protest against the Marxist insurgents. They maintain that the event was entirely apolitical and directed only at the rebel fighters, but in a statement on their website they denounce Chávez's "interventions in the internal matters of Colombia and, particularly, his declarations which seek to justify the Farc as a representation of the Colombian people".

Chávez's inflammatory comments about the threat from Colombia came two days after he declared that the Venezuelan armed forces were "on alert" against possible aggressions from the neighbouring country. In a televised broadcast, the president had warned: "We don't know how far it could go. We don't want to hurt anybody, but no one should make a mistake with us."

He added: "One day things will change in Colombia," referring to the cocaine-fuelled civil war that has raged across the border for almost 60 years. "Theirs is a war in which we cannot participate except as peacemakers."

His words have further aggravated the deepening diplomatic crisis with Bogotá. After successfully negotiating the release of two hostages held by the Farc, he requested that these narco-rebels be removed from lists of international terrorist organisations and expressed an ideological affinity with their insurgent cause.

"The Farc and [National Liberation Army] ELN are not terrorist bodies. They are real armies that occupy space in Colombia. That must be recognised. They are insurgent forces with a Bolivarian political project, which here we respect," Chávez said in his yearly address to the National Assembly on 11 January.

As the anti-Farc movement gathered global momentum through social networking sites such as Facebook, it was quickly seized upon by the Colombian government. On the day of protest, Colombian president Álvaro Uribe even delivered a message of thanks to marchers in the city of Valledupar. "Our gratitude goes to all Colombians who today expressed with dignity and strength their rejection of kidnapping and kidnappers," Reuters reported him as saying.

Back at the Valencia barracks, Venezuelan officials reacted truculently. Jesús González, the strat egic commander of the armed forces, rejected it as a "political ploy to try to identify 4 February with opposition to the Farc".

President Chávez reminded his army and onlookers of the history behind the day's cele brations. "The events of 4 February [1992] swept Venezuela into the 21st century. It was when the Bolivarian revolution truly began," he declared.

In recent years, the flamboyant Venezuelan president has used 4F to demonstrate his increasing regional influence and to launch stinging verbal attacks on his enemies.

While critics maintain that it is hypocritical for a democratic country to celebrate a coup, albeit a failed one, Chávez's supporters see it as the day that planted the seeds for Venezuela's ongoing socialist transformation. Chavistas call it the "Dawn of Hope" and regard it as a stepping-stone to true democracy for the poverty-stricken masses.

"It was the lightning bolt that illuminated the darkness," Chávez said in an interview with the Chilean author Marta Harnecker in 2005.

Continuing his speech to the military, the president maintains that 4F is not finished. "It reminds us we need to be even more revolutionary. My government is a child of 4F," he says.

After two years in prison, Chávez and his allies were released by presidential pardon in 1994 and began a new effort to take over the government, this time through democratic means.

"We realised that another military insurrection would have been crazy," Chávez said in 2005. "A large part of the population did not want violence, but rather they expected that we would organise a political movement structured to take the country on the right path." He came to believe, he has said, that the Bolivarian revolution had to be a peaceful one.

However, some scholars consider the Venez uelan government's decision to actively celebrate 4F a rewriting of history intended to indoctrinate the population.

Néstor Luis Luengo, a professor of sociology and head of research at the Andrés Bello Catholic University in south-west Caracas, believes commemorating the failed coup is a key element in Chávez's broader socialist agenda. "There is an ideological battle taking place in this country. If [the government is] going to push for more reforms, they have to change the ideology of the country and the historical events celebrated." It is in their interests, he says, to make 4 February a patriotic day.

Opposition leaders also criticise Chávez for using the commemoration of the failed coup as an attempt to politicise the military. "For us, the important thing is to have an armed force that is apolitical, modern and at the service of the Venezuelan people, and one that does not become a political party," said Julio Borges, leader of the opposition party Primero Justicia.

Other Chávez opponents are concerned at the militarism: "This government prefers to celebrate a day of violence. They should instead be celebrating the day he was democratically elected president," said Armando Briquet, secretary general of Primero Justicia.

A violent act

Chávez's supporters obviously disagree. Cruz Elena Peligrón, a civilian participant in the 1992 coup and friend and neighbour of Chávez in the 1990s, says: "We have always celebrated our independence day and that was a violent act. The US military commemorates wars like Vietnam and the Second World War. They say you have to fight for peace and unfortunately that's true."

Since Chávez took office in 1999, he has survived an attempted coup, oil strikes and referendums on his presidency. Last December, a package of proposed reforms to the constitution, which would have allowed him to stand for indefinite re-election, was defeated at the polls - his first political loss in nine years.

With Chávez's opponents invigorated by their poll success, this year's 4F festivities were notably restrained, taking place in a small pro vincial barracks instead of the grand military base at Fuerte Tiuna.

Venezuela's ambassador to the UN and former coup plotter, Francisco Javier Arias Cárdenas, said political priorities have changed: "We are no longer going to support unconditionally any segment of the Colombian military that has the objective of destroying either the Farc or the peace process in Colombia. Venezuela is just a third party in the civil war."

He concluded: "Of course we don't support guerrilla warfare, kidnapping or drug trafficking. But to end the war you don't necessarily need to end the Farc - just end the poverty, misery and violence that occur in Colombia every day. Both sides should go to the table and talk peace."

President Uribe maintains an unwavering zero-tolerance stance against the Marxist rebels and has shown much support for paramilitary forces that have been responsible for a catalogue of human rights abuses throughout Colombia's intractable civil war.

Meanwhile, Chávez's flamboyant militarism and allegiances with the Farc make dialogue between Colombia's warring factions seem less and less likely.