To what extent did the Soviet occupation of Afghanistan contribute to the collapse of the Soviet Union?

Question

To what extent did the Soviet occupation of Afghanistan contribute to the collapse of the Soviet Union?

Answer 1

It was a big drain on their economy and it also emboldened the people in the Soviet Union who sought independence for their Republic. They believed that the Soviet Union would be reluctant to engage in another conflict while they were still fighting in Afghanistan. 

Answer 2

To 'some' extent it contributed. It was a precursor of things to come for the Soviets. It was their 1st big decline and failure. But it started way back in 1979 while the Soviets were at peak power. The Soviet Union certainly could have withstood their 9 year failure in Afghanistan (1979-1987), but coupled with their failing economy, dissatisfaction of the Russian people, and especially with Reagans arms race... Afghanistan was one thing and the 1st thing that brought them down but not a main thing  

Answer 3

The occupation of Afghanistan drained Russia's economy and military.