Jānis Sārts’s grandfather was sent to Siberia by the Russians. His wife’s aunt was unlucky enough to be deported from Latvia, not only in 1946 but again in 1949 after a short reprieve. Sārts, now the director of Nato’s strategic communications centre of excellence in Riga, responsible for recording and responding to enemy propaganda methods, remembers the long queues for sausage and bread under the Soviet Union. “Sausage you would have once a month,” he recalls.

Sitting at a long table in a conference room at the whitewashed Nato headquarters, Sārts cannot see the logic of Russia invading Latvia in the near future, as it did Georgia and Ukraine, but he will not beat around the bush: “It is not at all impossible.”

Last week the centre of excellence in Riga unveiled the results of research into what it claims is a “preparatory information war” in Latvia but with, it emerges, much wider repercussions.

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One project examined 200,000 comments posted on Latvia’s three main online news portals between 29 July and 5 August 2014. It found 1.45% of those comments were from “hybrid trolls”, a phenomenon that came to light recently when it emerged that Russia had set up warehouses in which an army of bloggers sat day and night, charged with flooding the internet with comments favourable to Russian interests. But in some stories, more than half of the comments were by Russian trolls – identified partly by their poor grammar, repetition of content and IP address.

Five types of troll were found: the “blame the US conspiracy trolls”; the “bikini trolls” (adorned with images of young women who would gently ask targets to rethink their views); “aggressive trolls” determined to drive people off the web; “Wikipedia trolls” working to edit blogs and web pages to Russia’s advantage; and “attachment trolls”, who would post link after link to articles and videos from Russian news platforms.

The audience for the presentations – including diplomats and military officers – were told that, while the number of trolls might seem small, they were the “glue” for a wider project.

Kremlin-backed TV channels were jammed into the airspace, Russian-language newspapers disseminated stories and content produced in Moscow, while NGOs, funded by Russian money, offered up talking heads on every issue under the sun. Meanwhile, automatic “digital bots” were churning out messages influencing the search engines. “If you research for Ukraine, maybe the top 10 results will be those backed by the Kremlin,” said Sanda Svetoka, a senior Nato communications expert.

Speaking on Thursday, Sārts held little back: “What we have to do is understand the strategies, the methods, the tactics, and, of course, from that understanding create an ability to resist, respond, and win and protect our societies, the hearts and minds of our people, our value systems, the way our societies work.”

During an interview with the Observer he is equally frank. But his warning about the Russian threat is designed for ears outside Latvia. “I would say in the Baltics much of what we have seen has been going on for quite some time,” says Sārts, who was Latvia’s most senior civil servant at the ministry of defence until taking up his Nato role a year ago. “The new phenomenon really is that they are starting to replicate in other countries.”

And it is suggested the ambitions of the Kremlin know no bounds. “First and foremost in all the cases is that they do very careful vulnerability mapping,” Sārts says. “There are nuances with particular countries and there are generalities seen everywhere.”

What are the Russians preparing for? “For the unknown. It is establishing a network that can be controlled. You can use it as they have tried to do in Germany, combined with the legitimate issue of refugees, to undercut the political processes in a very serious way. Angela Merkel has been a very adamant supporter of continued sanctions against Russia.”

So is Russia punishing Merkel? “If it was just punishment, that would be OK, but it is testing whether they can build on pre-existing problems and create a momentum where there is political change in Germany.”

Sārts hesitates, stressing that he can talk only from his vantage point in Riga, as an expert in the field, rather than a Nato spokesman. “I think they test whether they can, in such a big country – with not so many vulnerabilities in normal times – actually create a circumstance through their influence where there is a change of top leadership,” he says. “They are using Russian speakers, social media, trying to build on the existing faultlines. Use the far right narrative and exploit that …

“In general terms, you can trace the funding of Russia to the extreme forces in Europe. Either left or right – as long as they are extreme, they are of possible use in their tactics … [But] we saw it in Germany. The best misinformation tool is when your opponent doesn’t notice. That is when it is most effective. I would submit that there are a number of countries who have not yet noticed, or have chosen not to notice.”

Facebook Twitter Pinterest Nigel Farage has made regular appearances on the Kremlin-controlled RT channel. Photograph: Vickie Flores/Rex Shutterstock

Sārts will not be lured into naming these nations, but is adamant Britain should not regard itself as immune. Saying he is aware that Labour leader Jeremy Corbyn has appeared on the Kremlin-run RT channel, formerly Russia Today, he adds: “One has to understand what RT is for and it is to gain influence.

“From the political sense you might be excited to ride an opportunity but, with that, you give to this source a legitimisation that can turn against you at a point because it is not objective journalism they are pursuing.”

Lieutenant-Colonel Simon West, a British army officer, is branch chief at the Nato centre. Sitting at his desk, he points a laser pen at a map of Europe and the countries on Russia’s western front immediately in the line of fire, which he says Vladimir Putin wishes to act as a bulwark against the encroaching liberal democracies.

Sweden and Finland are being bullied by tales of Nordic child abuse rings targeting adopted Russian children, he says; while the presence of Russia in the Baltics weighs heavy in everyday life (“I sometimes think I’m imagining it, but when I drove into the office today, the radio switched from music to a Russian news programme”). Ukraine, meanwhile, is being turned in the public perception from Russia’s closest ally, its “biggest brother”, into a “corrupt Nazi state”.

In Georgia, the Russians move the barbed-wire border every few weeks by 50 metres. The local Georgians make a fuss on television and the Russians win a propaganda victory. People are reminded that Georgia is a “dirty state”, he says, with unsure territorial boundaries which, if it joins Nato, could easily drag the organisation into war.

And further afield, in Britain? “Nigel Farage appears on RT quite a lot. Not as much as George Galloway, of course – a classic useful idiot.”

West adds that the strategic communications centre is yet to focus on Britain, but he believes it could be illuminating to track future money flows from Russia during the European Union referendum campaign.

Looking back at his map on his office wall, West says Russia’s genius is to always act within the threshold after which the west would have to act militarily. Or if it goes further, to give the west an opt-out by, for example, in Ukraine hiding their invading troops’ identity. But can he see such a scenario occurring in Latvia? “I can’t see it. My cleaner is sure they are coming, as I am sure many Latvians are.” West pauses, staring at the map. “I dunno, he’s mischievous,” he adds of Putin. “I’ve got a feeling of expectation that something is going to happen.”