Marxist Theories of International Relations

A central element of Marxist thinking is the tension between the means of production and the relations of production. What does this mean?
Marx said that capitalism is an inherently unstable system. What does this mean?
Explain the notion that Marxism is a school of thought with many variations.
Explain how world-systems theory can be seen as a direct development of Lenin’s Imperialism – the Highest Stage of Capitalism.
How did Antonio Gramsci explain why it was so difficult to promote revolution in Western Europe?