Question: Among the events that led to the creation of permanent counter-terrorism forces in major European countries were the Black September Organization was responsible for the massacre of Israeli Olympic team members and the assassination of the prime minister of which country?

Context articles: Munich massacre
Eliezer Halfin
Kehat Shorr
Operation Wrath of God
Yossef Romano
Jamal Al-Gashey
Yossef Gutfreund
Erinnerungsort Olympia-Attentat
Prime Minister's Office (Israel)
Black September Organization

The Munich massacre was an attack during the 1972 Summer Olympics in Munich, West Germany, at which eleven Israeli Olympic team members were taken hostage and eventually killed, along with a German police officer, by the Palestinian terrorist group Black September.
Eliezer Halfin (18 June 1948, Riga – 6 September 1972, Munich) was a Latvian-born wrestler with the Israeli Olympic team at the 1972 Summer Olympics in Munich, Germany.
 Along with 10 other athletes and coaches he was taken hostage by Palestinian Black September terrorists on 5 September 1972.
Kehat Shorr (February 21, 1919 – September 6, 1972) was the shooting coach for the 1972 Israeli Olympic team.
 He was one of the 11 members of Israel's Olympic team killed in the Munich massacre.
Operation "Wrath of God" (Hebrew: מבצע זעם האל‎ ‎ "Mivtza Za'am Ha'el"), also known as Operation "Bayonet", was a covert operation directed by the Mossad to assassinate individuals involved in the 1972 Munich massacre in which 11 members of the Israeli Olympic team were killed.
 The targets were members of the Palestinian armed militant group Black September and Palestine Liberation Organization (PLO) operatives.
 Authorized by Israeli Prime Minister Golda Meir in the autumn of 1972, the operation is believed to have continued for over twenty years.
Yossef Romano (also known as Joseph Romano or Yossi Romano) (Hebrew: יוסף רומנו‎ ; April 15, 1940 – September 5, 1972) was a Libyan-born Israeli weightlifter with the Israeli team that went to the 1972 Summer Olympics in Munich, West Germany.
 He was the second of eleven Israeli team members killed in the Munich massacre by Palestinian members of Black September during that Olympics.
 He was the Israeli weight-lifting champion in the light and middle-weight divisions for nine years.
Jamal Al-Gashey (Arabic: جمال الجاشي‎ ‎ ; born 1953) was a member of the Black September offshoot of the Palestine Liberation Organization and is the last surviving member of the group of eight Black September members who carried out the massacre of eleven Israeli athletes during the 1972 Munich Olympics.
 He is visible several times in videos of the event, identifiable by his blue and white striped jacket.
 During the abortive rescue attempt by Bavarian border guards and Munich police which resulted in the deaths of nine hostages and five of the Black September members, Al-Gashey was shot in the wrist attempting to aid a fellow Black September member.
Yossef Gutfreund (20 December 1931 – 6 September 1972) was an Israeli wrestling judge for his country's 1972 Olympic team.
 He was murdered in the Munich massacre by Black September terrorists along with 10 other members of the Israeli team.
The Erinnerungsort Olympia-Attentat is a memorial in the Munich Olympiapark for the victims of the Munich massacre during the 1972 Summer Olympics in Munich, West Germany, at which eleven Israeli Olympic team members were taken hostage and eventually killed, along with a German police officer, by the Palestinian terrorist group Black September.
Israeli Prime Minister's Office (Hebrew: משרד ראש הממשלה‎ ‎ ) is the governmental ministration office with the responsibility of coordinating the actions of the work of all governmental ministry offices, on various matters, and serving and assisting the Israeli Prime Minister in his daily work.
 Among other things, it is responsible for formulating the Israeli cabinet's policy, conducting its cabinet meetings, as well as responsible for the foreign diplomatic relations with countries around the world, and supervising and overseeing the implementation of the Cabinet's policy.
 In addition, it is in charge of other governmental bodies, which are directly under the Prime Minister responsibilities.
 Unlike many other countries, the Office of the Prime Minister of Israel does not serve as his residence place as well, and in addition to his daily work office, he resides elsewhere, at the official residence of the prime minister in Beit Aghion.
The Black September Organization (BSO) (Arabic: منظمة أيلول الأسود‎ ‎ , "Munaẓẓamat Aylūl al-aswad") was a Palestinian terrorist organization founded in 1970.
 It was responsible for the assassination of the Jordanian prime minister Wasfi Al-Tal, kidnapping and murder of eleven Israeli athletes and officials, and the fatal shooting of a West German policeman, during the 1972 Summer Olympics in Munich, their most publicized event.
 These events led to the creation of permanent, professional, and military-trained counter-terrorism forces of major European countries, like GSG9 and GIGN, and the reorganization and specialization of already standing units like the Special Air Service of the UK.