The difference between the troops and the brass

Was the chasm between the people in the field and the people in the Pentagon always so great?  Or has the air in Foggy Bottom become even more toxic? It’s hard to imagine the military 40 or more years ago making such a concerted effort to cover-up an investigation and promote a dubious person, just because the person fell into a politically favored class.  But what do I know?  Maybe you know?