[8] He was assigned for a time to the Office of Strategic Services (OSS), a forerunner of the Central Intelligence Agency (CIA), in Belgrade.

[7] Thayer served in London on the European Advisors Committee which drafted the German terms of surrender at the end of World War II.

[7][9] After the war, Thayer headed the OSS in Austria and served in 1946 on the Joint United States-Soviet Commission on Korea.

[7][10] He played a key role in developing the secret Office of Policy Coordination, later merged into the CIA, to counter and destabilize the Soviets (including its clandestine recruitment of former Nazis and collaborators for paramilitary operations).

"[17] They learned, for example, that during his OSS service "Thayer was waited on regularly by a native Yugoslav waiter named Marko, who was a known homosexual."

Thayer's marriage to Maria Petrucci, the daughter of an Italian diplomat, lasted less than two years, which one informant attributed to homosexuality, though she later denied this.

[21] McCarthy renewed and expanded his attacks following Republican gains in the 1952 elections when the new Secretary of State, John Foster Dulles, decided to co-operate with Senate investigators.

[22] Finally, at the end of March 1953, after much bureaucratic infighting, Thayer was forced to resign in order to win Senate confirmation of his brother-in-law, Charles Bohlen, as Ambassador to Russia.

[23] The Süddeutsche Zeitung regretted his departure and expressed concern that the effect on government operations of a "wave of McCarthyism ... must be devastating".

[27] Thayer wrote but did not publish an autobiographical novel based on his experiences as a victim of McCarthyism and the purge of homosexuals from government service.