Invasion today, as in the past, is usually the consequence of a shortage of resources (food, metals, oil, water), climate change (affecting food supply), overpopulation (also affecting food supply) or political upheaval. Although I do not speak as a military strategist, it would seem obvious that if, for any of these reasons, a state is forced into an expansionism, it will first look at their nearest neighbours and assess the chances of military success. It is obvious that before the introduction of airborne attacks, propinquity in the form of contiguous territory or short sea journeys have always been critical for a successful invasion(a) and the continued control of occupied territories. This is borne out by the simple historical fact that all the earliest empires, which were located in what we now call the Middle East, expanded through the invasion of its neighbours.
However, over-expansion can be costly and potentially dangerous. With particular reference to the fall of the Roman Empire, Rachel Nuwer noted in a recent BBC article(c) that. “By the end of the 100 BC the Romans had spread across the Mediterranean, to the places most easily accessed by sea. They should have stopped there, but things were going well and they felt empowered to expand to new frontiers by land. While transportation by sea was economical, however, transportation across land was slow and expensive. All the while, they were overextending themselves and running up costs.”
Many people think that military intelligence gathering is a relatively modern development. However, ancient documents, including the Bible, have accounts of spying thousands of years ago. Mary Rose Sheldon has produced an invaluable sourcebook on the subject, as well as a volume on Spies in the Bible, while Peter Dubovsky, in his Hezekiah and the Assyrian Spies, focuses on espionage described in 2 Kgs 18-19. It is reasonable therefore to assume that Atlantis also exercised due diligence and endeavoured to assess their opponents strengths and weaknesses before invading.
Boris Rankov has noted(b) in The Encyclopedia of Ancient History that military intelligence in ancient times had its value limited by the “slowness of communications, which meant that it was often out of date before any response could be brought to bear.” This, of course, ties in with the then established practice of invading those within your immediate proximity; supply lines are shorter and information more up-to-date. In turn, it implies that Atlantis was within relatively easy striking distance of Athens!
Even in modern times the same constraints determined the actions of invaders. Hitler could not have invaded Russia without first controlling Poland and Romania. Even expansionist Japan, although an island nation, expanded into Korea and Manchuria (China) and following the attack on Pearl Harbour spread even further within the same region.
The ancient land-based empires were dependent on military might, whereas others, such as the Phoenicians, expanded their influence through trade, supported by extensive merchant fleets. However, over time, Phoenician or more correctly Carthaginian rivalry with Rome led to disastrous wars.
One of the primary military concerns today, as in ancient times, will be to ensure that its men are fed and watered and consequently there will be a need to keep its supply lines as short as possible.
The nearest possible belligerent to the west of Athens was across the Adriatic in Italy. I argue elsewhere that according to Plato, southern Italy constituted part of the Atlantean domain (see Etruscans). I suggest that the Atlantean invasion of Greece was probably launched from there. The motivation is unclear, but we can speculate that success in Greece would have been followed by the control of the entire Aegean, including Crete, offering a huge expansion in trade.
The alternative is that the nearest part of Atlantis was elsewhere, necessitating the bypassing of other territories on the way and stretching supply and communication lines more than desirable. Italy looks the best bet, with forces added from the Atlantean HQ in Sicily or Sardinia, possibly travelling through the Strait of Messina, sometimes identified as the location of the Pillars of Heracles.
In the south, the Atlantean forces in North Africa (Ancient Libya), if not augmenting the attack on Greece, were probably planning their invasion of Egypt (Timaeus 25b & Critias 114c). Success there would have been followed by a two-pronged attack by both northern and southern Atlantean forces on the eastern Mediterranean coast, later known as the Levant, giving them total control of the eastern Mediterranean Basin.
Invasion requirements are the strongest argument against any of the fanciful Atlantis theories that place Plato’s Atlantis in Antarctica, the Andes, or North America. It is ludicrous to claim that any invasion force came across the Atlantic to attack Greeks and Egyptians. That there were remarkable early cultures in both North and South America is absolutely undeniable, however, it is foolishness to claim that they had any connection with Plato’s story.