Who did Nash believe was spying on him?

John Nash whose life is depicted in the biography and film “A Beautiful Mind,” is a mathematician who struggles with mental illness for much of his adult life. Nash suffered from auditory hallucinations and paranoia. Nash would behave on his mind’s interpretation of things.

His fear became prevalent because he thought he was being chased and observed by Russian spies which caused him to run away and become incognito; however, he believed that the Russians captured him and locked him in a hospital to keep him from doing top-secret government work.