By the 1970s, the Stasi had decided that the methods of overt persecution that had been employed up to that time, such as arrest and torture, were too crude and obvious. It was realised that psychological harassment was far less likely to be recognised for what it was, so its victims, and their supporters, were less likely to be provoked into active resistance, given that they would often not be aware of the source of their problems, or even its exact nature. Zersetzung was designed to side-track and "switch off" perceived enemies so that they would lose the will to continue any "inappropriate" activities.
In the Yalta and Potsdam conferences, the Allies established their joint military occupation and administration of Germany via the Allied Control Council (ACC), a four-power (US, UK, USSR, France) military government effective until the restoration of German sovereignty. In eastern Germany, the Soviet Occupation Zone (SBZ – Sowjetische Besatzungszone ) comprised the five states ( Länder ) of Mecklenburg-Vorpommern , Brandenburg , Saxony , Saxony-Anhalt , and Thuringia . Disagreements over the policies to be followed in the occupied zones quickly led to a breakdown in cooperation between the four powers, and the Soviets administered their zone without regard to the policies implemented in the other zones. The Soviets withdrew from the ACC in 1948; subsequently as the other three zones were increasingly unified and granted self-government, the Soviet administration instituted a separate socialist government in its zone.