Question

How did the Prague Spring lead to the downfall of the Soviet Union?

Answer 1

Everything I'm about to say comes from my skimming of the Prague Spring wiki page, so take that as fair warning

Answer 2

The Prague Spring refers to a period of political and social reforms in Czechoslovakia generally based on giving more rights to the people, increasing democracy and decreasing the influence of socialism.
This eventually lead to the Soviet Union invading the nation in order to prevent these reforms from taking place. It seems the Soviet forces underestimated how long it would take to stabilize the unrest, so perhaps that lead to destabilization down the line?

Answer 3

Also, a lot of citizens of the Soviet Union did not approve of the invasion, so perhaps that contributed as well. A contribution of diverted military resources and bad press as a result of the response to the Prague Spring could have played a part in leading the USSR to its downfall.

Answer 4

I definitely oversimplified and more than likely missed a few details, but that's the gist of it, from what I could gather