Istanbul

Istanbul in 1956 was a city very much affected by the Cold War. It served as a destination for Eastern Europeans being smuggled through the Iron Curtain and was a transfer point for smuggling from the Middle East to Europe. Most importantly, the 1950's was a time of growing American military and economic aid to Turkey.
Soviet and nationalist communist entities viewed the generous American support as a national security threat, leading to a heightened interest on their part in learning what steps the Americans were planning to take or the status of initiatives already underway.
In this novel's fictional scenario the close knit American expat community of Istanbul, composed of U.S. Consulate personnel, undercover operatives of other U.S. agencies, retirees, businessmen, students and others, is rumored to have a spy in their midst.
After a CIA agent is murdered while investigating the rumor, Alan Harper, a young CIA operative fresh from an assignment in North Africa, is tasked with finding out who ordered the killing while also being asked to take up where the dead agent left off.
The young Alan Harper, only a few years out of journalism school and the completion of his CIA training, undertakes his third major assignment; his first being his undercover work in Calcutta in 1955 in connection with the city's forthcoming municipal elections; his second being an assessment of the geopolitical status of the province of Cyrenaica, Libya, after Nasser's nationalization of the Suez Canal in 1956.
Teaming up with Harper during this new and dangerous assignment is Anne Small, a CIA agent based in Beirut who ostensibly works for UNESCO. She poses as Harper's girlfriend while Harper is purportedly in Istanbul to write a feature article on the growing popularity of Istanbul as an American tourist destination.