What caused the collapse of the Soviet Union in 1991?

Gorbachev's decision to allow elections with a multi-party system as well as form a presidency.

hope this helps

sure but add mine: melku504

explanation:

i'm in keystone 8th grade btw

it took two men to wrestle rome back from chaos and turn a republic into an empire. in the first century bc, rome was a republic. power lay in the hands of the senate, elected by roman citizens. but the senators were fighting for power between themselves.