That's not how it works. You know what it takes to reach that level? That means moving/dispersing your strategic forces around like mobile launchers and getting bombers on alert status getting important people moved all that is easily detected by US STRATCOM and other US intel agencies including European ones. If Russia was equivalent to DEFCON-2 Biden would be airborne and STRATCOM aircraft.
Here in San Diego Naval ships would be making a Beeline out of the bay right now.
We will know how the US has reacted only tomorrow though.
Or both could be at DEFCON 3 level.