the real reason Russia is invading is certainly because of the geopolitics involved
While the geopolitics issue is a better "excuse" than nazis, it's still just an excuse. How do we know this? Because there was and still is a 0% chance that Ukraine would EVER be allowed to enter Nato. LOTS of countries want to join Nato, but most dont meet the requirements, those that do meet the requirements willfully choose to remain neutral (Austria, Cyprus, Finland, Ireland, Malta, Sweden and a shit ton of others). I wouldnt be surprised to see some of these countries join Nato in the very near future given Russia's recent unprovoked actions. For example, why doesnt Russia itself join Nato? Because it cant, it doesnt meet any of the 3 requirements. Ukraine is FAR from meeting such requirements. I still believe that the true reason is nothing more than Putin's own ego. He wants to recreate the former USSR geographically. Period. It really is that simple.
I will mention that should things change in Russia, there is a possibility it could join Nato itself if it ever decides to adhere to the 3 requirements. That is an opportunity that every country on the planet has if they choose to do so and are successful in meeting the requirements.
From 2008 when it was announced that Ukraine and Georgia would be given NATO membership Russia made clear they considered this a line in the sand and an existential threat. In response to this NATO kept pushing it, culminating in the 2014 Maidan coup and establishment of the NATO-backed Azov regime that currently rules Ukraine.
Its been nothing but escalation from the war criminals and usurers who run the western regimes and their offer to Putin has consistently been "you'll eat shit and like it." Surprise, he didn't eat the shit!