The 1st Cold War never ended. US officials promised repeatedly not to expand NATO as the USSR was dissolving, and broke those promises almost before their next breath.
Simultaneously, we've been supporting fascists in Ukraine since WWII. So, NATO in Ukraine was seen as an existential crisis on Russia's doorstep.
Add fascist attacks on ethnic Russians in Donbass, & you have merely a continuation of WWII. Thanks, America.