MADRID—Europe is at war. Digital war. And it’s very much the same fight that’s taken place in the United States: facing an attack meant to sow distrust, heighten divisions, and undermine established democratic processes.

Here’s a chilling fact: At the height of the Catalan separatist crisis, analysis of more than 5 million messages about Catalonia posted on social networks between Sept. 29 and Oct. 5, shows that only 3 percent come from real profiles outside the Russian and Venezuelan cybernetworks. These are the conclusions of a report prepared by Javier Lesaca, visiting scholar at the School of Media and Public Affairs at George Washington University.

And there’s more: 32 percent of the messages investigated came from Venezuela—accounts linked to the Chavista regime of Nicolás Maduro. Thirty percent were born from anonymous accounts exclusively dedicated to contents of the Russian state media RT and Sputnik; 25 percent came from bots; and 10 percent from the official accounts of the two Russian media mentioned.

On the same dates, the geolocation data offered by social networks such as Twitter or Facebook show similar results: Excluding Spain, 13 percent of those who shared RT’s information about the illegal referendum in Catalonia were in Venezuela.

Based on these data, the newspaper El País concluded on Nov. 11 that, the “Russian network used Venezuelan accounts to deepen the Catalan crisis.” Hours later the government of Spain claimed that it has well-founded information that confirms a large number of messages with a Catalan secessionist bias in social networks comes from “Russian territory.” The possibility of Venezuelan involvement was left open.

What sort of fake news items are we talking about? Sputnik and RT played up the confrontations in Barcelona the day of the referendum that Madrid declared illegal, of course: “Police violence against peaceful voters.” But the website EUvsDisinfo.eu, created by Brussels to monitor “fake news” of Russian origin and respond to it, registered such propagandistic (and implausible) headlines as “Catalonia will recognize Crimea as part of Russia,” “Spanish is studied as a foreign language in Catalonia,” “European officials supported the violence in Catalonia,” or, “Also the Balearic Islands in Spain ask for independence,” a news item signed by the Russian agency Sputnik.

The propaganda campaign of Russian origin has not ceased, although it has been weeks since the referendum and the Spanish government’s response applying Article 155 of the Spanish constitution, which partially suspended the Catalan self-government, in order to call new regional elections in December.

The manipulative drift of RT led to the truly hysterical headline on Oct. 28: “Tanks in the streets of Barcelona: Spain and Catalonia on the verge of a violent outcome.”

There was no tank on any street in Barcelona, nor any violent outcome of any kind.

According to Spanish counterintelligence sources consulted by the investigative website El Confidencial Digital, the detailed analysis of information on Spain and Catalonia published on Russian media platforms in recent months shows that Russian disinformation is “shameless.” The newspaper adds that “in the moments of greatest activity,” up to 50 false or biased stories about the Catalan convert appeared each day.

On Thursday, Nov. 23, an expert from the Elcano Royal Institute, Mira Milosevic-Juaristi, appeared in the Spanish Parliament to analyze the results of her investigations into Russian interference in Spain’s affairs. According to the institute’s data, the presence of Catalonia in social networks increased by 2000 percent in September, while some messages from Julian Assange—suddenly converted to a leader favoring Catalan independence—were retweeted up to 60 times per second, which is only possibly using bots.

Milosevic-Juaristi believes that the “complexity of the technological means used” rules out the possibility that the messages may come “from an isolated individual or a patriot” and is inclined to see a “planned strategy” that has the “support of agencies close to the [Russian] government.”

Why would Russia want to interfere in Spanish territorial problems? Milosevic-Juaristi concludes that the Russian objective has not been the independence of Catalonia, as such. Rather, the Kremlin found in the secessionist cause an opportunity to “weaken” the European Union and “discredit” the European democracies.

Finally, Milosevic-Juaristi recalled that since 2014, Russia has included the “information war” in its official military doctrine. A war financed by the Kremlin that has as propaganda generators RT or Sputnik, which rely on its intelligence services, and that can spread its message through thousands of false profiles on social networks.

The war, of course, is not only about “information.” According to the most recent data from Spain’s National Cryptological Center (CNI), after the application of Article 155 of the constitution to stop the secessionists, hackers allied to or hired by Catalan separatists carried out 70 cyberattacks against websites of the central administration, judicial organs, political parties, and some private entities in the context of what they baptized as “Operation Catalonia,” backed by Anonymous.

The campaign lasted 10 days. The CNI reported that it detected and stopped those attacks in most cases, and thwarted all attempts to steal information.