I am not sure your timeline is correct. For example, https://www.nsa.gov/news-features/declassified-documents/ven... implies US counter-intelligence efforts against Soviets under the Venona project continued until 1980. There were and are doubtless other counterinteligence efforts that ran in parallel and continue to this day. Moynihan's "Secrecy" book explores in detail how intelligence information gets politicized and suggests some policies to minimize that. Using secrets for political ends no doubt occurred and continues to occur and is not limited to any particular party or government department. My point was that there is strong evidence for significant Soviet espionage activity, which the article implies was not the case.