“there have been enough strange aerial sightings by credible and highly trained military personnel”
IOW pilots and air crew are seein’ stuff they can’t explain.
Sighting of things unexplained happens all the time. Potentially threatening unexplained things might be an enemy. If you can't report it because it might be embarrassment, that might lead to missing something deadly.
In retrospect, it's hard to believe this can gone on as long as it has.
This reminds me of the old Sherlock Holmes mystery about the dog that didn't bark. The fact that pilots and radar operators were prohibited from reporting certain unknowns speaks to the magnitude of the "UFO" problem within the military. In other words, the importance of something "off limits" can be measured (perhaps imprecisely) by just how off limits it is.
I remember the "UFO" sighting at O'Hare seen by many civilians, pilots, and other professionals. Professionals were told that they "saw nothing" or else (per physicist Stanton Friedman). Makes one wonder about the source of that order.
Not saying that military is afraid of actual aliens, but they sure as hell were nervous about UFO's.