He was one of the key figures in the decimation of Moscow's many German Communist refugees during the Great Purge[3] as well as in the Red Terror; the witch-hunt by the Servicio de Información Militar for both real and imagined members of the anti-Stalinist Left within the International Brigade during the Spanish Civil War.

[4] Following the end of World War II in 1945, Mielke returned to the Soviet Zone of Occupied Germany, which he helped organize into a Marxist–Leninist satellite state under the Socialist Unity Party (SED).

In response, Mielke oversaw the 1961 construction of the Berlin Wall and co-signed standing orders for the Border Guards to use lethal force against all East Germans who attempted to commit "desertion of the Republic".

Mielke covertly trained and armed far-left guerrillas and militant organisations aimed at committing terrorist attacks and violent regime change in Western Europe, Latin America, Africa, Southeast Asia, and the Middle East.

Due to his close ties to former dictator Mengistu Haile Mariam, John Koehler has accused Mielke and the Stasi military advisors he assigned to Ethiopia under the Derg of complicity in the Red Terror, genocide, and many other crimes against humanity.

[7] During the later years of SED leader Erich Honecker's rule, Mielke was part of the small clique of Politburo members who made all consequential decisions on their own, alongside Joachim Herrmann and Günter Mittag.

According to Koehler, "In mid-March 1933, while attending the Lenin School, Mielke received word from his OGPU sponsors that Berlin police had arrested Max Thunert, one of the conspirators in the Anlauf and Lenck murders.

Although the Public Prosecutor of Berlin learned of Mielke's presence and filed for his extradition, the Belgian Government refused to comply, regarding the assassinations of Captains Anlauf and Lenck as "a political crime.

They horrified numerous formerly pro-Soviet Westerners who had been witnesses, including John Dos Passos, Arthur Koestler and George Orwell, and caused them to permanently turn against the U.S.S.R.[45] Mielke's belief in Stalin's official explanation for the defeat, that anti-Stalinists had stabbed the Spanish Republic in the back, continued to shape his attitudes for the rest of his life.

[49] That same month, Mielke's future handler, NKGB General Ivan Serov, travelled to Germany from Warsaw and, from his headquarters in the Berlin suburb of Karlshorst, divided the Soviet Zone into "Operative Sectors.

"[64] Also in 1949, Noel Field, an American citizen who had spied for the NKVD from inside the U.S. State Department, the Office of Strategic Services, and the CIA, fled from his posting in Switzerland to Communist Czechoslovakia after his cover was blown by fellow mole Whittaker Chambers.

After his interrogation in Budapest, Field was used as a witness at show trials of senior Soviet Bloc Communists who, like László Rajk and Rudolf Slánský, stood accused of having spied for the United States.

"[67] In August 1950, six senior SED members, including Willi Kreikemeyer, the director of Deutsche Reichsbahn and head of Berliner Rundfunk, were accused of "special connections with Noel Field, the American spy."

[71] After Soviet Premier Joseph Stalin died inside his Kuntsevo Dacha on 5 March 1953, the Central Committee of the East German Socialist Unity Party met in a special session and eulogized the dictator as the "great friend of Germany who was always an advisor of and help to our people.

[80] By the end of the meeting, only two Politburo members still supported Ulbricht's leadership: Free German Youth League chief Erich Honecker and Party Control Commission Chairman Hermann Matern.

[80] Meanwhile, Mielke informed a Party commission looking for scapegoats that his boss, Stasi Minister Wilhelm Zaisser, was calling for secret negotiations with West Germany and that, "he believed the Soviet Union would abandon the DDR.

Tapping about 100,000 telephone lines in East Germany and West Berlin around the clock was the job of 2,000 officers... Churchmen, including high officials of both Protestant and Catholic denominations, were recruited en masse as secret informants.

"[93] On Mielke's orders, and with his full knowledge, Stasi officers also engaged in arbitrary arrest, kidnapping, brutal harassment of political dissidents, torture, and the imprisonment of tens of thousands of citizens.

Mielke and Wolf provided money, training, and surveillance equipment to help build pro-Soviet secret police forces in Fidel Castro's Cuba,[95][96] Baathist Syria,[97] Sandinista-ruled Nicaragua,[98] Mengistu Haile Mariam's Ethiopia,[99][100][101] Idi Amin's Uganda,[101][102] Kwame Nkrumah's Ghana,[103] South Yemen,[104] and the Ministry of Public Security (MPS) in the Socialist Republic of Vietnam.

In what John Koehler has dubbed, "The Invisible Invasion", some West German citizens collaborated out of Marxist beliefs, but others were recruited through blackmail, bribery, career frustrations, or sexual favors provided by Stasi operatives.

The 1974 arrest and exposure of Günter Guillaume, a highly placed Stasi mole inside the Social Democratic Party, resulted in the resignation of West Germany Chancellor Willy Brandt and the discrediting of the latter's policy of Ostpolitik.

"[123] In a 1991 interview with John Koehler, Holocaust survivor and Nazi hunter Simon Wiesenthal said of the Stasi, "They not only terrorized their own people worse than the Gestapo, but the government was the most Anti-Semitic and Anti-Israeli in the entire Eastern Bloc.

"[124] During a 1979 visit to the GDR by senior PLO member Salah Khalaf, Mielke said, "We are paying great attention to the Palestine resistance and the other revolutionary forces fighting against the policies of the United States and against the provocations of the Israeli aggressor.

[126] Members of the West German Baader-Meinhoff Group,[127] the Chilean Manuel Rodríguez Patriotic Front,[128] and Umkhonto we Sizwe, the paramilitary wing of the African National Congress,[129] were brought to East Germany for training in the use of military hardware, insurgent tactics, and, "the leadership role of the Party.

[132] Colonel Wiegand revealed that Mielke and Wolf provided bodyguards from the Stasi's counter-terrorism division for Venezuelan-born PLO terrorist Carlos the Jackal[133] and Black September leader Abu Daoud[134] during their visits to the GDR.

"[137] According to John Koehler, "Increasingly concerned over the growing popular opposition, Stasi Minister Mielke early in 1989 ordered the creation of a special elite unit for crushing disturbances.

[149] According to Anna Funder, "The plans contained exact provisions for the use of all available prisons and camps, and when those were full for the conversion of other buildings: Nazi detention centers, schools, hospitals, and factory holiday hostels.

As his speech was broadcast live, Mielke began by using overly bombastic, flag-waving language, saying "We have, comrades, dear assembly members, an extraordinarily high amount of contact with all working people."

[177] In the meanwhile, the Federal Constitutional Court announced that Mielke had also been indicted for having ordered two terrorist attacks by the Baader-Meinhoff Group against United States military personnel who were stationed on West German soil.

The second was the attempted murder with an RPG-7 anti-tank rocket of United States Army General Frederick Kroesen, his wife, and the West German Federal Police (BKA) officer who was driving their armored Mercedes at Heidelberg on 15 September 1981.