maybe your analysis is a bit too simple?
1. Putin does not accept Kiev's drive to become a NATO member, and insisted onto it's neutrality, due to the 1991 treaty, that also defines the borders of Ukraine
2. Ukraine annulled the "neutrality clause" in 2010, therefore Putin does not accept it's borders - defined entirely by the Soviet Union and "granted" by Jelzin in 1991 under the pretext of Ukraine being a member of CIS, (Alma-Ata Declaration) Ukraine and Georgia had decided to resign their membership in 2018 respectively Georgia in 2009.
3. Taking the existence of the Baltic republics (never been CIF members) into account and already being NATO members - he certainly doesn't see Finland as an additional threat, but rather as an elongation of an already threatening NATO borderline towards Russia. (aside from one attack under Stalin) - there has never been a war or warlike tensions between Finland and Russia caused by the latter since 1939, and after that till 1944 it was Finland that had allied with the Nazis against Russia. (naturally hoping to regain lost territory).
4. That Putin isn't happy about Finland haven given up on it's neutrality - is understood, and he will also have to take the blame for that in the Duma.
CIS (The CIS Heads of States meeting on 26 August 2005 adopted several resolutions, including one on military cooperation and another on the fight against terrorism).
The CIS Defense Ministers Council met on 20 June 2007 to discuss military cooperation. Russian Defense Minister Anatoly Serdyukov said that the Council had created a specific military cooperation plan through 2010.
So Putin's stance is indeed very simple: if a member breaks the Alma-Ata-Declaration - okay, let's talk about the respective borders of e.g. Ukraine because the one it holds are those
of the Ukraine. And Putin went into action in 2014 e.g. by accepting the "independence declarations" of the Donbass and Luhansk republic and after occupying the Crimea - the Crimea
republic.....and.......
Okay back to war talk and who destroyed how many of what...