It was the largest movement of US troops in decades. On January 12, 2017, four years after the last American tank had been withdrawn from Europe, the US Army's 3rd Armored Brigade Combat Team was transferred to Poland. Over 3,000 soldiers, 87 tanks and hundreds of motor vehicles left the northern German port city of Bremerhaven to join local forces on the eastern Polish border. Photographers and camera teams were documenting the move and the public was allowed to watch as the political message to Moscow was intentional.

Miraculous multiplication of tanks

An obscure website in separatist eastern Ukraine reported a miraculous multiplication of tanks. The "Donbass News agency" wrote that the United States had transferred 3,600 tanks to the Russian border. The report claimed that the massive military march was directed against Russia.

Ben Nimmo from the Atlantic Council is one of approximately 400 experts who help a small team of 11 people at the EU Foreign Service identify fake news. He uses the tank story to show how news stories are passed around from one website to the next and then politically instrumentalized. The Donbass News Agency did actually get the figure of 3,600 tanks from a real source. If you count all the vehicles, including the ones in reserve in the Netherlands, they add up to 3,600; however, the figure includes jeeps, trailers and Humvees. All the vehicles were suddenly seen as tanks.

It was obvious that this false report was published intentionally. "This is typical of fake news," said Nimmo. "There is a kernel of truth in them and it is then embellished by a lot of rubbish."

Journey through the web

The tank story later appeared on a Canadian website known for spreading conspiracy theories. It reacted to the tank story with the headline: "Political insanity." The story was blown up yet again, shared with other pro-Russian websites and then finally picked up by the Russia's Ria Novosti news agency.

This is actually the key to the problem, explains Ben Nimmo. The news agency gives the fake article credibility. He pursued the story's path further to the former Soviet Union, to Latvia, and the website of a Norwegian communist who later deleted it after it was obvious that the story was unfounded.

"That is exactly where the danger lies," Nimmo said. "Fake news stories are as credible as their distributor and not the original source. And Ria Novosti obviously made the story look true."

How do you fight fake news?

In addition to the propaganda originating from Russian sources, countless fake news stories are going around because money can be earned from advertising on the websites that publish the false stories. In order to identify the fake news, one has to search for evidence and follow a story step by step from its source. "Spreading fake news is a serious allegation. You have to prove it," said Nimmo. Several European governments, like those of France and Germany, have set up special task forces to deal with the problem.

Nimmo says that anyone who knows their way around the Internet can search for fake news. "You do not need to have a master of technology. You just need time and you need to be familiar with social media outlets and how they work together - everyone knows how to do that."

However, experts are still needed to solve difficult and unusual cases, Nimmo said, but they must also teach interested citizens the art of uncovering fake news. If more people got involved, the detection rate would improve and then the political effect of fake news would wane.

Nimmo had one more piece of advice to offer: "The key is emotion. If a story appeals to your feelings, be they anger or rejection, and not your thoughts, then you have to check it."

Europe's enemies

"The dangerous thing is that the governments of several countries want to undermine the EU. Russia is the most important example but Turkey is also involved," said Marc Pierini from Carnegie Europe, adding now that the US government is publishing its own confusing reports, the situation will not improve.

"Russia employs a great deal of people and spends a lot of money to spread fake news; the EU and its members states cannot keep up," said Pierini. That is why everyone must help - the media and civil society - and be particularly cautious before elections, he added, because this modern form of propaganda has become a political instrument for several governments.

Pierini does not see any danger in the present flow of fake news from Russia. "What I fear is reports from the National Front in France, [Prime Minister Viktor] Orban in Hungary and others who are close to Russia or funded by Russia," he said. "They tell people, for example, that they would be better off outside the EU and without the euro. And because the traditional left-wing or conservative parties have lost their value, there is a real danger."