American spies sabotaged the reactor in Chernobyl
The history of the U.S.-Soviet Cold War is full of incidents of espionage, sabotage, elaborate intelligence and counter-intelligence schemes, and even proxy wars. In this context, American spies are the obvious suspects in the Chernobyl disaster. The CIA worked actively to infiltrate and undermine Soviet institutions throughout the Cold War, so why not at Chernobyl? The disaster, after all, was a major blow to the Soviet Union's infrastructure, prestige, and international reputation, and presented no risk of harm to the distant United States.