WI/AHC the Roman Republic didn't expand after the first punic war and continued to play an important regional role instead of destroying Carthage and trying to take over the world. However you cannot destroy the Romans (but a change of power to an emperor is allowed).
You have absolutely, totally thrown Roman history off-course.
Sicily was the first proper imperial territory of Rome. It was when Rome switched from being a hegemonic power within the Italian peninsula to an imperial power on the Mediterranean stage.
In fact, you might have just saved the Roman Republic.
Or, arguably, put it in a far weaker position.
Unless you can manage to create an opponent for Rome that is both non-threatening enough not to lead them into confrontation (and Romans scared easily) and strong enough not to be conquered, I don't think that is feasible. The Roman Republic well before the Punic War had warfare as a central factor in advancing political careers. If you were a leader and did not get to go to war, you would always be at a crippling disadvantage to those that did. As a result, Rome's armies went to war regularly, even this early. Later in the republican era it would be almost every year. Unless this starts looking counterproductive (from the POV of a Roman aristocrat), it won't stop, because the Roman reaction to losing typically was redoubling the effort. And I don't see any power in the ancient Mediterranean standing up to Rome militarily in the long run.
Actually there was a POD to stop the Roman expansion.Unless you can manage to create an opponent for Rome that is both non-threatening enough not to lead them into confrontation (and Romans scared easily) and strong enough not to be conquered, I don't think that is feasible. The Roman Republic well before the Punic War had warfare as a central factor in advancing political careers. If you were a leader and did not get to go to war, you would always be at a crippling disadvantage to those that did. As a result, Rome's armies went to war regularly, even this early. Later in the republican era it would be almost every year. Unless this starts looking counterproductive (from the POV of a Roman aristocrat), it won't stop, because the Roman reaction to losing typically was redoubling the effort. And I don't see any power in the ancient Mediterranean standing up to Rome militarily in the long run.
Actually there was a POD to stop the Roman expansion.
But it is an internal one.
Why was it Rome and no other city-state who seized the Mediterranean?
There was a feature that only Rome had (among other cities) - it was comparatively easy to get a Roman citizenship. It was partially because of the traditional Roman corruption (the nobles were interested in making as much as possible of their freedmen full citizens so they would vote for them). And partially it was intentional - Rome desperately needed citizens for their endless wars.
That was why Rome could afford a lot of disastrous defeats and after that it was able to 'redouble the effort'.
So take away the possibility of Rome to make new citizens 'out of nowhere' and you will stop it's expansion. We will have Rome resembling something like Athene or Carthage or Syracuse.
Let's say the 'true Romans' force the laws like 'Rome for the Romans' and the power base of the state will diminish dramatically. After one major defeat they will break like Athene was broke after Syracuse' expedition. They will not have enough citizens to join the army.
Without the possibility to produce new Roman citizens 'out of the thin air' (from the freedmen and children of freedmen and out of the free non-Romans) to replenish the Roman armies the Roman state might fall apart. I agree.That could do it, but it would also destroy the Roman empire over the medium term. Integration in Italy was far from complete, and wouldn't be until decades after the social war. The Roman state's ability to integrate defeated powers into its many-tiered system was what enabled it to sustain its long and often disastrous wars. If it just played at collecting subjects Hellenistic-style, the bonds would not hold. A Rome based on that foundatiopn would have fallen apart at the very latest in the second punic war, probably earlier.
Let's say the 'true Romans' force the laws like 'Rome for the Romans' and the power base of the state will diminish dramatically. After one major defeat they will break like Athene was broke after Syracuse' expedition. They will not have enough citizens to join the army.
Actually there was a 'genetic, familial basis for Romanity' after the first punic war.Such a Rome, I think, is not possible. You need to go as far back as the Founding itself.
I mean, what we have of pre-Gallic invasion Rome is unrelaible, at best, but Rome itself was never based on the tribal roots that a lot of other states of the period were based on. It was intimately related to the 'anybody who is willing to submit to our state' idea that Rome had been based on since the Kings, and getting rid of that idea is probably impossible. There was no genetic, familial basis for Romanity. It was all based, ultimately, on loyalty to the Roman state.
In other words, making such a Rome would basically make such a thing not Rome. You would end up with a TL based on a Veii, or an Italian Athens, rather than Roman TL.