There are many theories on why Rome fell.
The history channel gives 8 reasons…
Invasions by Barbarian tribes
Economic troubles and over reliance on slave labor
The rise of the Eastern Empire
Overexpansion and military overspending
Government corruption and political instability
The arrival of the Huns and the migration of the Barbarian tribes
Christianity and the loss of traditional values
Weakening of the Roman legions
All of these contain part of the answer, but what is at the core of all of these reasons?
This is a great video that explains the core reason for the fall of Rome.
How does the US right now compare to the Roman Empire when it fell?