End of Superpower Collapse of the USSR

The USSR (Union of Soviet Socialist Republics) was born in 1917. And it was implemented in full force in 1922. The USSR flag is hoisted for the last time in Moscow on December 25, 1991, the USSR disappears from the world map, the Soviet Union was once considered the largest country in the world, the Soviet Union was an expanse of 22 million kilometres. After the collapse of the Soviet Union, new 15 countries are born, it is a matter to think that what happened in 1991 that the most powerful country USSR collapsed, how such a huge empire disintegrated in an instant,