The key to victory for this game is capturing enemy capitals.
For the CP, that is a ground unit mission (extreme odds against CP capturing London or Washington).
The gambit, though, is a CP naval strategy that disrupts Allied ground defenses. Allies have a huge naval advantage.
If the CP can threaten the Atlantic, contest the Mediterranean, and cause the Allies to spend too much on naval units, the CP have a chance to win.

Has anyone else tried a French tactic of (F1) A. Taking Spanish Morocco, B. Mobilizing Portugal and consolidating the transport fleet; (F2) Borrowing the mobilized Portuguese to swing down to SZ 23/ Togoland with a significant force; (F3) Move French transports back towards Canada and using the French African Task Force to Gain IPCs for France and to eliminate the Germans in Africa?

Excellent battle analysis, ColonelCarter.
To Frederick II: France should always take Spanish Morocco, and I agree that the US should not attack Spain.

We played OOB Rules and the RR was declined.
Another interesting twist was that Britain reinforced Russia overland through Afghanistan, and the US reinforced Russia via Karelia.
I would like to try the CP Big Navy strategy again with the Allies abandoning Russia.

This weekend I tried a Big Navy strategy for the Central Powers, combined with a Capture Egypt strategy for the Ottoman Turks.
CP were able to hold SZ 17. Turkey took Egypt, which then allowed a successful assault on India. Britain could never obtain superiority in the Channel, as Germany was building Battleships and running the minefields to hold SZ 8.
This was fun and different, but ultimately unsuccessful. Russia survived (barely), and the tradeoff in not buying land units meant defeat, first for Germany and then Austria (13th round).

One of the most frustrating things about Diplomacy was that after finally rounding up enough players for a 7-player game, the rules explanations took so much time. We rarely finished a game. I wrote a “Simplified Rules for Chess-style Diplomacy” years ago to introduce new players to a quicker game. Once a few games played to conclusion, you had a player who would be interested in the full length game.
The simplified rules used dice rolls for an order of play, and all spaces on the board were available for all units (no fleet transports were needed.)

France:
The powerful French Navy MUST help clear the Atlantic for safe shipping to the continent.
Then, a French reinforcement of Albania and/or Egypt is a good tactic.
France needs Infantry buys for several rounds before advancing on the Germans, in my opinion.

One nation at a time: Russia first.
All ships need to make sacrificial attacks on the first round, to attrit the Central Powers navies.
All artillery units should be pulled back, consolidated, and used for survival as the CP forces get close to Moscow.
The ideal situation is to buy just enough fighters to have air supremacy at that time for that battle.
Russia should mobilize Romania on Round 1.
I prefer to send all Sevastopol forces to Mesopotamia to assist the Brits. Repayment comes when the Brits send relief forces to Karelia.

Transports may carry two units; the units may be of any type (infantry, arty, tanks, fighters).

Looking for more feedback on this strategy; I am hoping it could be a game-changer for the CP.
Even if Britain builds totally in India, they still take casualties conquering Persia. As soon as that happens, the Turks have the opportunity to make a massed attack into Persia and then India (T5?). The Turks will have to shuttle forces from everywhere else, and will have to forfeit everything but Constantinople, Ankara, Mesopotamia, and Bulgaria; is this risk worth the reward?
Can the Central Powers take Russia with Germany and Austria-Hungary only?
Can CP win the game with the Indian production center stabbing them in the back?
As I said earlier, the strategy looks good in theory, and the smart Allied players can put pressure on Constantinople, but I have had only partial success with this and I am looking for ideas to improve it. Maybe a retreat from Bulgaria? Strong A-H naval presence in SZ 17? A-H support from Ukraine-Sevastopol?