When the news broke that a Putin-Trump summit would be held in Helsinki, some comments made my ears prick up. In the international media there was talk of Finland having been chosen as a venue because it is “neutral ground”, a country deemed to have a history of neutrality, and where east-west meetings had been held during the cold war. But Finland today is nothing of the sort. It is a member of the European Union. It is not somewhere in a grey zone between Europe and Russia.

My schoolbooks all said that Estonia had voluntarily joined the Soviet 'family'. Of course, this wasn’t true

Dredging up phrases from the era of Finlandisation is unfortunate. Language shapes reality, and our recent history still makes Finland behave in a certain way. For example, Finland is not a member of Nato, and that may have something to do with Russia’s constant blustering, apparently convincing us that joining would bring the sky crashing down on our heads.

When I was born in Finland in 1977, the country was deep in the throes of Finlandisation. Even though Finland had retained its independence, the Soviet Union used its influence to interfere in its weaker neighbour’s affairs. This was Finlandisation. In addition to foreign policy, this practice also affected national defence, the economy, education, the press, publishing, and even which foreign artists visited Finland or which movies we were able to see.

The peace settlement that followed the continuation war (in which Finland and Nazi Germany fought as co-belligerents against the Soviet Union from 1941 to 1944) gave free rein to communists in our country. In the arts, which drew me from a young age, communist paeans rang out loud and clear. Academic research wasn’t safe, either. Honest study of the Soviet Union’s catastrophic economy and its society was ill-advised if you valued your career.

My mother was born in Estonia and came to Finland after marrying my Finnish father. For years, she kept worrying about her family still living in the USSR. This weighed on what we could discuss even in Finland: voicing the wrong opinion risked bringing down retribution on our loved ones. Estonian emigrants had formed lively communities in other countries, but this was impossible in Finland. Taking part in international friendship societies with the Baltic countries was considered “anti-Soviet agitation”, something which had to be stamped out according to the strict provisions of the peace settlement.

Being Estonian in Finland could be a lonely experience. My schoolbooks all said that Estonia had voluntarily joined the Soviet “family”. Of course this wasn’t true, but Finnish schools hewed closely to the tenets of Soviet historiography. The backdrop to this was the treaty Finland had signed in 1948, called the “agreement of friendship, cooperation, and mutual assistance”: it allowed the Soviet Union to hold Finland in a tight grip. The Finnish National Board of Education, which reviewed our textbooks, abided closely to the requirements of the treaty, and Soviet authorities were only too happy to offer additional guidance.

Through schoolbooks, Finlandisation became an integral part of education, contributing to shape our national identity, historical memory, and language. And although our books provided ample space for discussion of problems in the United States, they always cast the Soviet Union in a positive light.

Facebook Twitter Pinterest Finnish refugees during the winter war with the Soviet Union. Photograph: Gamma-Keystone via Getty Images

However, there were exceptions to the party line: the 1939 Molotov–Ribbentrop pact (between Hitler and Stalin) and the existence of its secret protocol – to carve up Poland and the Baltic states and others – weren’t expunged from our books, even though the Soviet Union demanded it. And we held tight to our core national stories, such as the heroism of Finnish troops during the winter war of 1939-40. Of course, that Soviet attack on Finland was always described in the passive voice, to avoid stating directly who was to blame. Soviet propaganda claimed Finland had started the war – a version we couldn’t possibly accept. Our war veterans, my Finnish grandfather among them, knew the truth.

Few Finns were direct eye-witnesses to what life was like in the Soviet Union, because travel to the east was restricted. As a result, parts of the population gradually began to believe the Finlandisation narrative. Not long ago, I ran into a Finn who still held on to the rosy picture of collective farms depicted in the geography books of his generation. My Estonian grandparents lived in a kolkhoz (a collective farm), and things were far from rosy. Estonians knew all about Soviet reality, so Finnish naivete seemed absurd to them. My family was well aware that the KGB read every letter we sent to our relatives, but many Finns around us only thought we were paranoid.

Wearing a bridle such as this for decade after decade affects the language and the mindset of a people. We still don’t know which decisions made during that period were based on real threats or on self-censorship and delusion. These are the most treacherous consequences of Finlandisation.

Once the Soviet Union collapsed, Estonia immediately moved to wipe away all traces of the Soviet occupation it had endured. Soviet-era leaders were stripped of power, and even the Estonian language was updated to fit the reality of an independent nation. Finland didn’t follow suit, though. Maybe it didn’t seem necessary in a country that had maintained the symbols of its independence throughout the cold war. But independence means more than flying your own flag – it surely also encompasses respect for moral values and freedom of expression – and those were precisely the things that Finlandisation damaged.

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Finland was a psychological laboratory for the reach of Soviet power, a place where Moscow could conveniently study the impact of one its favourite tools: reflexive control – in which a subject is led to take a certain decision (apparently independently) by controlling of the information they receive. Today’s Russia used this method in the US in its effort to help Donald Trump become president.

Finland’s Finlandisation served Moscow’s agenda well during the cold war, because it looked like a Nordic democracy and it created the impression the Soviet Union was able to live peaceably with those on its borders. No wonder Putin’s regime seems tempted to duplicate that scenario today in parts of Europe – not least in Ukraine. As a Finn, I know how bad a solution that would be.

• Sofi Oksanen is a Finnish-Estonian novelist and playwright