What's the best analogue to think about this?
While Germany was effectively de-nazified after ww2 Russia never de-stalinized or made amends for it's imperial stance. You really have to think of the Russian state you would think about Germany if it was run by third reich institutions.
His reign was linked to very good relations with Moscow. He probably played both sides, but was in fact many ways enacting policies that were pleasing to Moscow. In the 50's this probably helped to stop explicit invasion.
The president of Finland Tarja Halonen supported the ratification of the Ottawa treaty banning all use of landmines in Finland in 2011. This was promoted as a benevolent act by many parties. Given that Russia had invaded Geoergia 2008 this can be in retrospect considered suicidally deluded or treasonous position.
The latter one is perhaps the most egregious example of the actions of parties one would at bare minimum describe as "usefull fools". The only party that would ever benefit from Finland banning landmines is Moscow.
3)
Finland was planning a new nuclear plant starting from 2010. The tendering was won by Rosatom in circumstances that implied high favoritism toward the Russian state actor.
In 2014 after Russia invaded Crimea several municipalities pooled in extra capital to the process.
Luckily this plant project has been stopped and will never be built.
Things like this could go on and on. But the whole point of clandestine subversion is that it's clandestine and KGB archives are probably sadly not available for academic study for decades if ever.