What Destroyed the Roman Republic?

[Frodo]

What ultimately destroyed the Roman Republic?  And is it an appropriate analog for our own? 

[Blue3]

The Western Roman Empire never really fell, it just evolved into a much more decentralized, feudal society overrun with newcomers. The Vatican survives as an official remnant of it.

The Eastern Roman Empire survived until Ottoman conquest, and even then Russia claims to be a surviving remnant of it, or Turkey itself.

[Frodo]

I was asking about the republic, not the Empire.

[Blue3]

Again, they seamlessly evolved. Augustus didn't even think of himself as really an Emperor.

[Frodo]

Again, they seamlessly evolved. Augustus didn't even think of himself as really an Emperor.

Let’s try this -think of the period between Sulla’s march on Rome, and Octavian finally gaining sole mastery over the Roman state after vanquishing Mark Antony and Cleopatra.  

That is the timeline my question is in reference to.

[True Federalist (진정한 연방 주의자)]

The Carthaginians.

The manpower shortages of the Punic Wars and their aftermath led to the Marian reforms which created the permanent military dependent upon not the Senate but their own leaders. If Rome had been able to limit itself to the Italian peninsula, I think the Republic could have survived.