Which event directly contributed to the end of the cold war

The main events that marked the end of the Cold War were the fall of the Berlin Wall in 1989 and the breakup of the Soviet Union in 1991.

The Berlin Wall had been the main symbol of the Cold War. It had kept people from Eastern Europe, which was communist, from escaping to the West. When the Wall came down (along with other border barriers) it meant that people in the East could now leave. This pretty much meant the communist system was dead.

The death was confirmed in 1991 when the Soviet Union fell apart. This made the remainder of the country (mostly what is now Russia) much weaker. It also marked the end of communist rule.