Why did Communism and the Soviet Union collapse by 1991?

The Cold War came to an end when the USSR had lost its will for empire led by Gorbachev. It could not sustain the resources needed to pursue an empire it no longer felt it needed, it couldn't compete with the West and it needed a domestic change. First of all, the invasion of Afghanistan forced the USSR to evaluate its situation. It was a battle over the Soviet influence in Afghanistan and third world …

…in Malta in 1989, Shevardnadze was able to announce that the superpowers had 'buried the Cold War at the bottom of the Mediterranean'. When Mikihail Gorbachev became leader of the USSR in 1985 he represented a new generation within the Politburo. His determination to implement a reform of the Soviet system led to a fundamental shift of emphasis, which brought about, not just an end to the Cold War, but anso an end to the Soviet Union.