For those who do not know the reference, it comes from the stories of the second Persian invasion of Greece, as recorded by Herodotus. It is, I think, difficult to realize what these battles looked like. Suffice it to say that all of the Star Wars franchise and others owe a tremendous debt to this history.
The Persians had sent a comparatively small (for them) number of troops into Greece/Hellas and were repelled at Marathon over odds that look like a Jr. High football team defeating the winners of the Superbowl. They went back, regrouped, and launched a second attack.
When the Persians were in the process of sending their second invasion, Athens sent a delegation to Delphi to ask Apollon what they should do. The response was unequivocal and terrifying.
" “Why sit you, doomed ones? Fly to the world’s end, leaving
Home and the heights your city circles like a wheel.
The head shall not remain in its place, nor the body,
Nor the feet beneath, nor the hands, nor the parts between;
But all is ruined, for fire and the headlong God of War
Speeding in a Syrian chariot shall bring you low.
Many a tower shall he destroy, not yours alone,
And give to pitiless fire many shrines of gods,
Which even now stand sweating, with fear quivering.
While over the roof-tops black blood runs streaming.
In prophecy of woe that needs must come. But rise,
Haste from the sanctuary and bow your hearts to grief.” (Herodotus, VII, 140, trans., Selincourt)
This is not ambiguous. Athens was going to be utterly destroyed. So, the Athenians deliberated and did a lot of sacrifices and went back as suppliants for a second reading to see if they could get anything more from Apollon that would help them. After all, they were the city devoted to Athena and Apollon, Himself, had both given them their first courts, assisted in the development of democracy (the rule of the people) and their constitution, and was the divine ancestor of the people. Both Athena and Apollon have a strong relationship with Democracy.
The Athenian delegates were granted a second reading.
“Not wholly can Pallas win the heart of Olympian Zeus,
Though she prays him with many prayers and all her subtlety;
Yet will I speak to you this other word, firm as adamant:
Though all else shall be taken within the bound of Cecrops
And the fastness of the holy mountain of Cithaeron,
Yet Zeus the all-seeing grants to Athena’s prayer
That the wooden wall only shall not fall, but help you and your children.
But await not the host of horse and foot coming from Asia,
Nor be still, but turn your back and withdraw from the foe.
Truly a day will come when you will meet him face to face.
Divine Salamis, you will bring death to women’s sons
When the corn is scattered, or the harvest gathered in.” (Herodotus, VII, 141, trans Selincourt).
The delegation went back to Athens and there was a debate in the ekklesia. The debate centered upon what is the "wall of wood?" Themistocles held the day by saying that clearly the physical city of Athens would be destroyed, but the wooden wall was referring to the triremes, the ships, and that the second prophecy gave both the location (the straits of Salamis) and the time (two options) of a stand, but that they should evacuate the city and run. The ekkesia agreed and decided to make their stands in ships against a vastly superior navy in the straits of Salamis. The Athenians won over odds that make Star Wars look realistic.
However, acting correctly on Apollon's prophecy involved a massive shift in thinking for the Athenians. The argument was that it was the people and Athena Herself that constituted Athens, not a particular location. They abandoned the city (which was utterly destroyed by the Persians), but they took the holy xoanon statue of Athena from the old temple and took the people. Wherever they were, together, that was Athens. Then the citizens went onto the ships, where they had more maneuverability and had an advantage from knowing the straits and being great fishers. And they won against impossible odds.
The question I feel compelled to ask right now is, what is our wall of wood? I do think we are given one. According to Apollon, it was Athena (and, honestly, Him), using their power to sway things on the inner planes and move probability as best as possible. It doesn't mean that there is not destruction...awful, horrifying destruction...but Athens was victorious in the end from using power in ways that their enemy never dreamed about. I think this is also a possibility for us, here, in one of the incarnations of Athens. I feel it. We have to figure out, what is our wall of wood?