Or, at least, if the ill intent required immediate action on their part, something would have happened. They might be grooming us for some longer term purpose (like dinner;-))
I'm not a trusting sort, so if there is something other than just enemy-developed craft involved, I am suspicious as to motive.
And, if it is enemy craft, we are possibly in worse trouble.
If it were an enemy craft (Russia, China, Nazis from Antartica) I think our folks would have been told to engage. But that hasn’t happened.
With skunkworks usually 10-15 years ahead of traditional technology in the past, it would not shock me to know that they figured out some high tech, magneto drive propulsion.
I am more interested than concerned. If it ain’t us...there is little you and I can do about it. Until then, I will keep reading and watching to see what we can see.