https://globe.adsbexchange.com/ (click U to show only military traffic)
No matter what time or date that it is there is always some activity even when it is minimal, but currently the closest spot with a military transponder switched on is Brazil/Europe and a US Herkie over Okinawa...........
Something is definitively up!!
Welcome to planefagging.
This situation you describe is not, at all, unprecedented.
Possibly, but I usually check air activity a few times a day and I have never seen it this empty, I mean it's not just the US but no activity even CLOSE to the US..... Short of Brazil and what appears to be a low altitude helo(probably coast guard) over FL that just went up(not like they won't do rescue if they have to) the entire continent and surrounding seas is empty...
It's pretty early still