Wow Nick, you seemed to have put alot of thought into this and I definatley waiting to see the TL actually come to fruition. But I am wondering with a stronger Athenian "Empire" to actually give Phillip a run for his money, might they adopt the tatctics and formations of the Macedonian Phalanx? Might Athens still want to conquer Persia? And what of Carthage?
Thanks. I'm in the midst of doing some research so I won't make any predictions about the TL itself. It will come, though.
On the question of Philip and the Athenian Empire, an Athenian victory in the Peloponnesian War probably precludes the rise of Philip II as we know it. Philip learned a lot about Greek politics and tactical innovation from Epaminondas when Philip was a hostage at Thebes as a youth. Thebes / Boeotia is certainly going to need dealing with, but without the overstretch of the Spartan hegemony, its OTL rise is out the window.
That being said, the basic question of whether the Athenians will adopt new tactics is a good one. To be more sucessful, the simple answer is yes. There will be a couple competing innovations. First is the use of light troops, usually peltasts but also slingers and javelineers and archers. OTL Isocrates scored the first victory over a Spartan hoplite force by another Greek force when his peltasts defeated a
mora of Spartans at Lechaeum during the Corinthian War. These troops benefit from being more mobile than hoplites and were usually cheaper; mercenaries in the 4th century seemed to have preferred to arm themselves as peltasts.
Next is the use of cavalry. OTL Thucydides most stringent critique of the Athenians' force in Sicily seems to be that it lacked a sufficient force of cavalry. Some scholars seem to think that Athens held back what cavalry it had, but one might also conclude that Athens didn't have a very large cavalry force to begin with. In order to have a chance of subduing Sicily or the tribes of the Northern Aegean coast (Thrace and Macedon), Athens will need a substantial cavarly. I plan to have some fun with Xenophon in this regard.
The final component is a twofold change in mentality: professionalism and a doctrine of combined arms. I feel that given the example of the Athenian navy, with paid rowers, a professional standing army (drilled and paid for their service) has a good chance of growing up. The crucial battle will be with the upper clases, since a change away from hoplite militias will probably be seen as a complete class revolution, both in terms of the prestige of bearing hoplite arms and in terms of an potential for an increased tax burden. By a doctrine of combined arms, I mean two things really: armies comprising different kinds of troops rather than formed around one group and the coordination of tactical movement on the battlefield. In a classical hoplite battle, there
might be a cavalry skirmish before the battle as the armies approach one another, but funadmentally, the two armies line up across from each other and begin shoving in a homicidal version of a rugby scrum. Epaminondas signalled a change as he began to use different formations (a column en masse) deployed with particular tactical targets. Epmainondas didn't invent this so much as combine a number of different practices. Philip did the same while also pioneering a cavalry force, a professional army, and a reliable logistics operation. Philip and Alexander's battles also involve a good deal more movement and command on the battlefield itself, particularly because of the need to time a cavalry charge and position the infantry to be "the anvil" for it. I think it's pretty clear that this development will continge on military leadership at the time; I could see things evolving a little more piecemeal for Athens.
On the future conquest of an Athenian Empire, Persia is an obvious candidate. First, though, will probably come its role in the Peloponnesian Wars. There's no guarantee that they will break from their neutrality and ally with the Spartans, but it might be a convienient occurence. Persian involvement will break the Peace of Callias that had held since the 450s and ended the Persian Wars. It also gives the islanders something to fear (making them cling to Athens if she's smart). The Persian also made a habit in the 4th century of dominating Greece by dictating the terms of peace settlements: indeed, the dictum of autonomy incoporated in the King's Peace became a way for the Artaxerxes to ensure that if Persia couldn't conquer the Greeks, the Greeks would remain divided. Add to these calculations the frequent calls by 4th century orators (particularly Isocrates) for a pan-hellenic crusade against the Persian (to enrich the Greece due to the poverty betokened by decades of constant warfare) and I think some kind of reckoning is coming. I doubt the Athenians pull off an Alexandrian scale conquest, if only for the simple reason that their general will be more subordinated to Greek views by necessity. No guarantee that a rogue general doesn't plunge into a rump Persian Empire to forge his own kingdom, however. Most likely, there will be some kind of rump state. Egypt is probably freed in a revolt, but only under in formal influence of Athens. Athens probably acquires the coast of Asia Minor (on both the Mediterranean and Black Seas) and perhaps the interior.
Sicily is the key to any conflict with either Carthage or Rome. The easiest way for Athens to win the Peloponnesian Wars might be to engineer a victory at Syracuse in 415, but that's a little too wankish. The POD I'm working on will probably entail a very different kind of expedition (much smaller and only Alcibiades); I'm still not sure how things will work out. I'm think, though, that the Athenians organize some kind of league for the Sicels and those Greeks seeking to resist the power of Syracuse. I'm not sure if the Carthaginians invade in 408(ish) per OTL, since I feel that invasion was betokened by the failed Athenian attempt. I think the Carthaginians do come at some point soon; the Athenians probably are called in to help at just the point that the might finish up the conflict in Greece herself. I'm optimistic that Athenian naval strength could keep the Carthaginians at bay; I'm also toying with the Athenians moving into Syrasue to overthrow a tyrant there. In short, Sicily will end up under Athenian protection, but probably not Athenian rule. This ensures Athenian merchants have access to Sicilian, Egyptian, and Black Sea grains--the three major breadbaskets.
The probelm is that early on Carthage and Rome (the latter taking the place of the Etruscans) allied to contest powers to the east in the Western Med (and Sicily). Hence, there will be some interesting showdowns. Athens will probably grow to have prestige invested in the fate of Sicily, but the long term future of its Empire is its ability to incorporate the mainland Greeks and to expand into the Balkans. The latter is to me the hardest part, since it will entail discovering something about the tribes living there and how willing they might be the Hellenize. I think these are probably eastern Celts, so there's all kinds of interesting possibilities. In short, though, a Mediterranean with a powerful Athenian Empire heading an amalgated Greek Confederacy is probably going to develop into an early state system. (Sort of like Robert's Ancient Egypt TL).