"With all the ins and outs of China Watching--the layers of secrecy, the shifting political winds, the analysis of obscure propaganda articles, the scrutiny of leadership appearances--those less close to the China scene are tempted to view the China problem as insoluble and to write the Chinese off as "inscrutible." China watchers, of course, do not have that luxury, and most of them would disagree that the Chinese are impossible to understand. It may seem ridiculous to others that China watchers have learned to military officials from enlisted men, when ranks were abolished and insignia removed, by the number of pockets on their tunics,or that some China watchers have noticed a remarkable correlation between those Chinese leaders who wear sunglasses in public and those who eventually lose their jobs. That is, after all, the unique feature of the China watching business: there are almost no clues that are not worth following up. On those rare occasions when there is solid information about a major development, the often divided China watching community can usually agree on its implications and on Chinese motivations. It is not hard to understand the Chinese; it is just hard to get information about them."
final paragraph from the secret document by Gail Solin, declassified by the CIA in 1994.
Spring 1975: 18-40-4: The Art of China-Watching, by Gail Solin