He’s describing something that’s been going on since at least the 1940’s, and probably before that.
Doesn’t know what they are, no reason to believe they pose any threat, and we don’t have the capability to do anything about it.
But we have people who pretend they just made a discovery and something must be done about it.
I would argue that Trump changed the landscape and allowed for a massive release of belief within the military pilot community.
As for a ‘threat’...why? Nothing appears to rank more than exploration or understanding another species.