What was the largest Soviet intelligence gathering operation during the Cold War?

• A. Operation RYAN
• B. Operation Unthinkable
• C. Paris Charter (1990)
• D. Pentagon Papers

Answer: (A)

Think about scale and purpose: the question asks which Soviet effort aimed at collecting intelligence during the Cold War was the largest. Operation RYAN was a massive, coordinated push by the KGB and other Soviet security services to map Western nuclear forces and how NATO would respond in a crisis. It pulled together human intelligence networks, signals and technical intelligence, and extensive resources across Europe and beyond to uncover details about the U.S. and NATO’s missiles, early-warning systems, command structures, and potential decision-making processes. Not only did it strive for a comprehensive picture of Western military capabilities, it operated over several years with wide reach, making it the largest Soviet intelligence-gathering effort of the era.

The other options don’t fit the same pattern. Operation Unthinkable was a British postwar contingency plan, not a Soviet intelligence operation. Paris Charter is a 1990 post-Cold War treaty, again not an intelligence campaign. The Pentagon Papers refer to a U.S. government study whose leak revealed American policy debates—not a Soviet operation.