At the time of his defection, Pacepa simultaneously had the rank of advisor to President Nicolae Ceaușescu, acting chief of his foreign intelligence service, and a parliamentary undersecretary at Romania's Ministry of Interior.

On 1 December 1918, Transylvania united with Romania, and in 1920, Pacepa's father moved to Bucharest and worked for the local branch of the American car company General Motors.

In October 1959, Minister of the Interior Alexandru Drăghici appointed him as head of Romania's new industrial espionage department, the S&T (short for Știință și Tehnologie, meaning "science and technology" in Romanian) of Directorate I.

From 1972 to 1978, Pacepa was also President Nicolae Ceaușescu's adviser for industrial and technological development and the deputy chief of the Romanian foreign intelligence service.

[11] According to Pacepa, "Radu" was a Romanian name used as a reference to "radiation", with the intention to lead the target to cancer which would result in death within months after the exposure.

An article published by The American Spectator in 1988 summed up the devastation caused by Pacepa's "spectacular" defection: "His passage from East to West was a historic event, for so carefully had he prepared, and so thorough was his knowledge of the structure, the methods, the objectives, and the operations of Ceaușescu's secret service, that within three years the entire organization had been eliminated.

At least two squads of murderers have come to the United States to try to find him, and just recently one of Pacepa's former agents — a man who had performed minor miracles in stealing Western technology in Europe at Romanian behest — spent several months on the East Coast, trying to track him down.

[14] Documents found in the Romanian intelligence archives show that the Securitate had given Carlos a whole arsenal to use in "Operation 363" to assassinate Pacepa in the United States.

In 1987, Pacepa wrote a book published in the United States by Regnery Gateway, Red Horizons: Chronicles of a Communist Spy Chief.

[19] On 1 January 1990, the book began being serialized in the new official Romanian newspaper Adevărul (The Truth), which on that day replaced the Communist Scînteia (The Spark).

Far-right propaganda website WND introduced it in August 2016, as follows: "This November's election spells 'LOOMING DISASTER,' warns former communist spymaster and disinformation expert, Gen. Ion Mihai Pacepa."

In a 2006 article, Pacepa describes a conversation he had with Ceaușescu, who told him about "ten international leaders the Kremlin killed or tried to kill": László Rajk and Imre Nagy from Hungary; Lucrețiu Pătrășcanu and Gheorghe Gheorghiu-Dej from Romania; Rudolf Slánský and Jan Masaryk from Czechoslovakia; Mohammad Reza Pahlavi, the Shah of Iran; Palmiro Togliatti from Italy; US President John F. Kennedy; and CCP Chairman Mao Zedong.

[22] In a review of Pacepa's book published in Human Events, Michael Ledeen, former adviser for terrorism to President Ronald Reagan, writes: "A new book from General Ion Mihai Pacepa is cause for celebration, because he is among a tiny handful of people who know a lot about the intelligence services of the Soviet Empire, and because he writes about it with rare lucidity, always with an eye to helping us understand our world.

Pacepa painstakingly takes us through the documentary evidence, including invaluable material on Soviet bloc cyphers that throws new light on Oswald's letters to KGB officers in Washington and Mexico City.

"[24] Publishers Weekly stated "those inclined to suspect a conspiracy was behind JFK's murder will likely remain unpersuaded by Pacepa's circumstantial, speculative case" and that Programmed to Kill offered "no convincing Soviet motive for the assassination.

[21] In a 2006 article written during the Second Lebanon War, Pacepa wrote that the Soviet Union spread anti-Semitic propaganda across the Middle East to increase hatred for Jews, and by extension Israel and America.

In a 2007 article, he stated: "In my other life, when I was at the center of Moscow's foreign-intelligence wars, I myself was caught up in a deliberate Kremlin effort to smear the Vatican, by portraying Pope Pius XII as a coldhearted Nazi sympathizer.

Moreover, Pius was being lauded for his wartime efforts to protect religious minorities by, among others, President Roosevelt, Winston Churchill (who described him as "the greatest man of our time"), and Albert Einstein.

Stalin's disinformation efforts were rejected by that contemporary generation "that had lived through the real history and knew who Pope Pius XII really was," Pacepa explained.

[30] Pacepa wrote during October 2003 that it was "perfectly obvious to me" that the Russian GRU agency helped Saddam Hussein to destroy, hide, or transfer his chemical weapons prior to the American invasion of Iraq during 2003.