[4][6] During the Second World War, between the ages of 14 and 15, Wegener was briefly a compulsory member of the Hitler Youth and, living near Berlin, endured the relentless Allied air raids.

[2][4] In 1949, Wegener's home state of Brandenburg fell within the borders of communist East Germany (German Democratic Republic), where he began his studies in economics.

[3][4] In the early 1950s, as a member of an anti-communist group, he distributed dissident leaflets against the Socialist Unity Party of Germany (SED) in the Soviet-occupied sector of East Berlin.

[2][3][4] He was subsequently arrested for "socially hostile activity" after the group was informed on, initially imprisoned in Potsdam and later in Brandenburg.

Due to a lack of opportunities for advancement, Wegener applied for a career as an officer in the Bundeswehr and the Federal Border Protection (BGS, Bundesgrenzschutz).

[2][3][4] In 1972, he was training at the NATO Defense College in Rome, Italy, before returning to Germany shortly before the 1972 Summer Olympic Games.

[2][3][4] While serving as an adjutant to Federal Interior Minister Hans-Dietrich Genscher, he witnessed the failure of the regular Bavarian State Police in the face of an unprecedented threat from Palestinian terrorists during the hostage-taking of the Israeli Olympic team—a type of threat previously unknown in Germany.

[2] Two weeks after the disaster, Genscher, in agreement with Wegener's suggestion, entrusted him on 26 September 1972 with the rapid formation of the specialized counter-terrorism tactical intervention unit, Border Protection Group 9 (GSG 9, Grenzschutzgruppe 9), appointing him as its commander.

In the early 1970s, counter-terrorism units were still a relatively unheard-of form of combating terrorism, with the only truly established groups at the time being Israel's Sayeret Matkal, which had some experience in counter-terrorism and hostage-rescue, and Britain's Special Air Service (SAS), albeit with experience primarily in guerrilla warfare.

[5] Counter-terrorism and tactical policing specifically were still relatively unheard-of methods, and no military in the world had a unit specialized in handling hostage crises.

[1][12] In an interview in November 2000 with Holger Lösch from Bayerischer Rundfunk, Wegener was asked: "You are an intimate connoisseur of military history.

[4] From the 1980s onwards, he lived in Windhagen in the Westerwald, gave lectures, and became a member of the political party Christian Democratic Union of Germany (CDU).