The excellent book “Silent Coup: the Removal of a President)” by Colodny and Gettlin begins with the Pentagon’s spy in the White House, a junior officer who manned a communications office IIRC.
The senior military had noticed back-channel communications going on between Red China and someone in the White House. This was while we were busy fighting China’s ally North Vietnam and the military were concerned that they might have discovered a traitor. So they spied on these communications.
This led to a discussion of some select young military officers who acted as liasons between the White House and the Pentagon. One such Naval officer was Bob Woodward. Among the White House officials Woodward briefed was Alexander Haig.
Woodward then left the Navy and went to work at the Washington Post, teamed with Carl Bernstein. And then came Watergate and fame for one-time Naval officer and White House briefer Bob Woodward.
Yes, it was an excellent book chock full of many details and revelations.