With Russian intentions playing a key role in present day headlines, this review of how well various intelligence methods worked against the Soviet Union is timely and essential reading for anyone whose work or life may be affected by future Russian activity. In other words, nearly everyone in Europe and North America. This document from the CIA's Historical Review Program provides insights into intelligence sources and analysis related to the Warsaw Pact and Soviet military activities during the years 1955-85. It discusses the role of clandestine reporting, specifically highlighting the contributions of Col. Oleg Penkovskiy in providing valuable information on Soviet military doctrine, strategy, and capabilities. The document also touches on the Cuban Missile Crisis of 1962 and the importance of accurate intelligence in verifying the removal of Soviet missiles from Cuba. Additionally, it discusses the challenges and importance of estimating the strength and mobilization capabilities of Soviet and Warsaw Pact forces during this period. This information is crucial for understanding the dynamics of the Cold War and the military strategies employed by both NATO and the Warsaw Pact. "Scope Note: This study focuses on the contribution of clandestine source reporting to the production of finished intelligence on the Warsaw Pact's military doctrine, strategy, capabilities, and intentions during the period 1955-85. It examines products of CIA and national intelligence estimates (NIEs) of the Intelligence Community (IC) writ large. It includes more than 1,000 declassified CIA clandestine reports and CIA finished intelligence publications. Some of the finished intelligence publications were produced after 1985, but none of the clandestine reports. Although the focus of the study is on the contributions of clandestine human sources, the clandestine and covert technical operations such as the U-2 and satellite reconnaissance programs yielded a treasure trove of information." This annotated edition illustrates the capabilities of the AI Lab for Book-Lovers to add context and ease-of-use to manuscripts. It includes several types of abstracts, building from simplest to more complex: TLDR (one word), ELI5, TLDR (vanilla), Scientific Style, and Action Items; essays to increase viewpoint diversity, such as Grounds for Dissent, Red Team Critique, and MAGA Perspective; and Notable Passages and Nutshell Summaries for each page. Publication date of this edition is May 9, 2024, to coincide with the 81st anniversary celebration of Soviet victory over Germany.