It was a test of some tech of our own, clearly. Maybe a little messing with the Rooskies heads for laughs.
But it also risks messing with the heads of our own people (this is Andrews AFB after all.)
Our tech wasn’t capable of those maneuvers then and isn’t now.
Was that sarcasm? Um, no. Not in 1948, just over a year after 'Roswell'. If it was, then the WWII 'foo fighters' were ours, too. That's stretching credulity to fantasy. Denial is a warm blanket, but it's an order of magnitude worse to be an active participant in government gaslighting.
Earth is a biologically toxic oasis in this corner of the universe and, I suspect, far rarer than our scientists' little brains can conceive. There is a reason we continue to be gaslit on the topic; nobody will know for sure until they CHOOSE to be forthcoming (likely not in my lifetime).