How did the soviet invasion of afghanistan contribute to the fall of the soviet union?

1.the red army lost its strength and reputation.
2.the soviet union used nuclear weapons illegally against afghanistan.
3.the united states provided no military aid to afghanistan, thereby lengthening the conflict.
4.the soviet economy crumbled further due to the heavy military cost of the invasion.
5.eventually, afghanistan managed to gain the support of many soviet satellite states.