Carthaginian ability
Some good points posted.
Perhaps the success of victorious Carthaginians would depend upon what they did with Rome and how they administered Italy.
My visualization would be a victory over Rome in the second Punic war. Hannibal was already in Italy and the master of the countryside from 216 BC (after Cannae) to about 213. The name of the faction in Carthage that opposed Hannibal and denied him the support and reinforcements he needed to lay effective siege to the Italian cities isn’t known to us, but if instead they had put their energies into building a new fleet capable of, at least countering the Roman superiority at sea, the Romans could have been defeated.
The form of government in Carthage and Rome was not too different. A Senate that held the power of the wealthy families, a popular assembly of lesser citizens with sufficient property qualification, and two Suffetes who administered as Consuls did in Rome. There was also a Commission of Ten, which later grew to one hundred and which controlled the Suffetes, but my old set of Britannicas (1950 – good for accounts of earlier times) doesn’t account for interactions between these organs. Very likely the system changed under the stress of the wars.
My point in bringing up that bit of history is to suggest that Carthage could have controlled Rome and its possessions in a similar way to Rome’s control over Carthage after the second Punic war – by allowing local government but having a veto power over the enactments of its Senate, and a limit on its military power. In OTL, that system lasted 60 years before Rome found a pretext to destroy Carthage. My suggestion would be that Rome and Italy continued to blossom, even under Carthage and the resulting empire satisfied the ambitions of the best men of both. Ergo, they have the commercial savvy of Carthage and the organizing drive of Rome.
Which Greeks? A good question, but in 213 BC the Seluecids, the Ptolemies, and the successors of Macedonia in Greece and Anatolia were all still significant powers. Between them, the Carthaginians and their Roman clients could have played off one against the other and gradually conquered them all (or made them clients, or protectorates, as was Roman policy.) Syracuse could have flowered again without Roman domination, surely the home of much Greek genius and A-H what-ifs.
The genius of a society depends upon its ability to nurture and satisfy its most able sons (isn’t that what neo-liberal economics is all about?) Carthage had a good run for about 650 years, so it must have had the flexibility to adapt to new ideas and advantages as much as Rome did. I agree that its eyes would have been more on seaborne trade than on dominating the land with roads and marching legions, but their conquest of southern Iberia was a land campaign.
Would they have ventured across the Atlantic? Since my belief is that Columbus would have never ventured out without the stories and experience of the Portuguese who fished the Grand Banks for cod in the fifteenth century it could have depended upon the appetites of Europe more than the vision.
Kester.