The butterfly effect. The aftermath of Alexander's conquests sees a Ptolemaic push east that I neglected to mention, which prompts the Carthaginians to turn more and more warlike. This prompts the Romans to start doing the same as well, which will pose interesting questions for the Second and Third Punic Wars. Specifically, since Carthage is building a stronger power base, a Roman conquest will be harder, and there may be a Carthaginian Byzantine equivalent that survives for a century or so before the Romans ultimately finish it.
I see. But why exactly should a Ptolemaic push east make the Carthaginians who were a long way west become more militaristic?
Even if the Phonecians became more militaristic this should not impact on Carthage. Why should the Phonecians react in this way when they did not in OTL?