Espionage -- United States -- Case studies 2 Spies -- United States -- Biography 2 Spies -- United States -- History Espionage -- United States -- History 1 Espionage -- United States -- History -- 20th century 1 Espionage -- United States -- History -- 21st century 1 Espionage, German -- United States -- History -- 20th century 1 more ... Intelligence service -- United States -- History -- 20th century 1 Military intelligence -- United States -- History 1 Spies -- Communist countries -- Biography 1 Spies -- Communist countries -- History -- 20th century 1 less ...