If you Google "the collapse of the Soviet Union", you will find numerous references. And that's just the tip of the iceberg. So it's certainly not too early to ask, and probably not too early to answer.
Basically, the Soviet Union was an artificial construct of one large country and 15 smaller ones, whose main commonality was their control by the largest one. This construct depended on continued Soviet expansion, which the Reagan Doctrine halted. When Gorbachev tried to institute a more open, democratic society as the basis of reform, he fatally loosened the bonds of force that had held the "Union" together before the economic reforms had a chance to do their work.
The Soviet Union was split apart by "centrifugal" forces because "socialism," the glue mentioned in the Bryant thesis that held it together, was too weak. Perhaps more to the point, the revolutionary fervor and "class consciousness" reported by Bryant in the early days of the Revolution that motivated it had mostly disappeared by Gorbachev's time. Put another way, the problem was not that socialism in Russia was "premature" in Russia as Bryant claimed. Instead, its power was "real" (as she observed) but had outlived its usefulness by the early 1990s.
Basically, the Soviet Union was an artificial construct of one large country and 15 smaller ones, whose main commonality was their control by the largest one. This construct depended on continued Soviet expansion, which the Reagan Doctrine halted. When Gorbachev tried to institute a more open, democratic society as the basis of reform, he fatally loosened the bonds of force that had held the "Union" together before the economic reforms had a chance to do their work.