The Berlin Wall

Built in 1961, the Berlin Wall was used by the soviet side of  Berlin , the German Democratic Republic (GDR), to avoid capitalism to reach all the city, including the Eastern Part. It was used to ban any kind of change from one side to the other, mainly because the Western Part, the German Federal Republic (GFR) had a higher and much more balanced state of living, and many people wanted to move there. Due to this, the Stasi was founded, also known as the secret police of East Germany. The Stasi looked for "betrayers" of the Communism, who wanted to move to the Western Part, and they guarded almost every building that held people that could be suspicious. Trust died with this, and people betrayed each other by telling the Stasi who was leaving or trying to escape.