WASHINGTON—An investigation triggered by the contents of computer files captured during a raid on a guerrilla camp in Ecuador has now suggested a Venezuelan link between the ETA terrorist organization in Spain and the Revolutionary Armed Forces of Colombia, or FARC. A Spanish court’s decision to indict 13 Spaniards and Colombians as a result of that investigation should shame those who questioned the validity of the computer files at the time of the raid. Among those indicted is Arturo Cubillas Fontan, an ETA member employed by Venezuela’s Ministry of Agriculture and married to Goizeber Odriozola, the chief of staff of Hugo Chavez. Cubillas, believed to be the main contact between the FARC and ETA, is accused in the indictment of coordinating the training of ETA members in urban guerrilla warfare. The indictment also alleges that the FARC sought logistical help from ETA in Madrid in connection with an alleged plot to assassinate Colombian President Alvaro Uribe.

The Spanish investigation got under way thanks to evidence obtained by Colombia after the 2008 raid on the camp controlled by Raul Reyes, a key FARC commander. Colombian troops found 17,000 files and 37,000 documents in three satellite computers, two external hard disks and three memory sticks. Once Dipol, the Colombian secret service, studied the content, Interpol was brought in to authenticate the files and confirm that Colombia had not tampered with them. Colombia then discreetly shared relevant parts with the countries named in the files.

What was disclosed in the media was only part of a gold mine of information about the structure, the funding and the international connections of the Colombian terrorists. Venezuela immediately began a campaign to discredit the notion that those computers existed or, if they did, contained incriminating evidence. Allies of the Chavez regime, including governments, political leaders, intellectuals, nongovernmental organizations and some media outlets, were recruited to feed the campaign.

The idea that computer files could survive an attack by Super Tucano fighters and Black Hawk helicopters was ridiculed. The notion that contacts between Ivan Marquez, a FARC representative, and Chavez were registered in writing was scoffed at. How could Venezuela give FARC $300 million and serve as a conduit for the arming of Colombian terrorists with weapons imported from Russia, and leave proof of the triangulation in a laptop? The Organization of American States did not move a finger in the face of such a blatant violation of the 2002 Inter-American Convention Against Terrorism.

And yet the evidence was overwhelming. Among other witnesses, Bertrand de la Grange, an authoritative investigative journalist, gained access to the files—which had survived the attack because they were held in metallic suitcases. His first reports were published in Mexico’s Letras Libres and then picked up around the world. They explained the “five rings” of the FARC’s structure, including “Ring 3,” which operated out of Venezuela with Chavez’s help, and “Ring 5,” which spread its tentacles to 15 countries, among them Spain. The author concluded that there was “a network of international complicity of unsuspected dimensions.”

I asked de la Grange how decisive the information in the computer files was for Spain’s National Court’s investigation. “It was the main evidence,” he told me. “Those files had already led to the arrest of Remedios Garcia for aiding FARC in Spain and helped dismantle several networks of support for FARC in Europe.”

Venezuela’s ties to FARC are ancient. In December of 2004, Colombia arrested Rodrigo Granda, FARC’s chief of international relations, after bounty hunters captured him in Venezuela and took him to the border. Julio Montoya, of Venezuela’s MAS party, revealed that some 500 FARC members had been granted Venezuelan citizenship and operated on the Zulia-Tachira corridor along the border with the two countries.

Chavez’s ties to terrorism go beyond FARC and ETA. A few months ago, New York District Attorney Robert Morgenthau accused Venezuela of helping Iran circumvent international sanctions in connection with its nuclear program. According to Morgenthau, a Venezuelan barred by the U.S. Treasury from conducting business here because of his terrorist connections, Ghazi Nasr al Din, is working under a false name at the Venezuelan embassy in Lebanon.

The political significance of the Spanish National Court’s indictments cannot be underestimated. Spain’s left-wing government has been a friend of Cuba and Venezuela; it even sold Chavez weapons a few years ago. Madrid has resisted attempts by the European Union to denounce Venezuelan and Cuban human rights violations. Faced with such massive evidence coming out of its country’s own courts, how can the government maintain its policy without paying a devastating price at the polls?