What are the factors that led to the fall of the soviet union?

Whose writings were the source of the idea that people have a right to abolish and replace a government that violates their natural rights?

In the 1980s, more russians worked to encourage change in the government by a) establishing a new political system. b) rallying for democratic reforms. c) supporting the democratic system. d) resisting gorbachev’s reforms.

Which is true about the monroe doctrine?