Books on Soviet espionage/counter-espionage in Washington -- your chance to recommend!

Just finished reading Yuri Shvets' Washington Station. Good book that details the typical cycle of a late Cold War KGB agent: early eagerness, attempts to impress bureaucracy met with indifference, followed by later disaffection and eventual defection to the West.

Best revelation in the book: despite all the attempts to recruit well-placed higher-ups, bureaucrats and academics, the best intelligence was gathered by a regular janitor who emptied the trash in DC defense contractor offices.