Brezhnev was already likely senile when Soviet troops invaded Afghanistan in December 1979;
his aged successors Andropov and Chernenko were unable to get the troops out of Afghanistan or do anything to save the fast declining Soviet state.
Segment 25d Fall of the Soviet Empire gives us the end of the USSR as we know it. It fell apart.
The republics all ultimately seceded, using a right granted them by none other than Vladimir Lenin himself when the Soviet Union was founded.
Isn't it ironic? In 1985 Mikhail Gorbachev inherited a regime with a stagnant economy,
massive and expensive military commitments, a corrupt and top-heavy bureaucracy, and a populace that no longer cared about anything.
By introducing perestroika, or restructuring to the economy, and glasnost, or openness, to political life,
Gorbachev hoped to jolt the Soviet Union back on the path toward Communism and it didn't work.
Segment 25b Homo Sovieticus
As the Soviet state approached its fiftieth birthday in 1967, it could look with pride on some of its accomplishments.