Not sure why this seemed unlikely to you, given that Russia has already invaded Ukraine and has been conducting war there for 8 years. Putin controls the media that Russians consume and has been striving to reconstitute the USSR for years. Further, he is building an alliance with Xi and China, who like him want to add outside territories (Taiwan), want to expand the model of dictatorship, and want to destabilize the international rule of law paradigm. He has been indoctrinating Russians to believe that the West is responsible for his surrounding Ukraine, and will blame the West if/when he invades. China will help him out financially to further their own ambitions in Taiwan.