Babylon declared war on me. Hammurabi had about thirty battleships and destroyers, which SANK MY ENTIRE FRENCH INVASION FLEET. I quit the game again after that happened.
But a couple days later, after recovering from the shock, I loaded the save again, calmer. Babylon just sank the transports and meager escorts; they were not loaded yet and the tanks and infantry were safe. Good thing, because I need them to repel that invasion stack above.
Finally, Babylon's timing was fortuitous. It happened during my 2-man Golden Age. Here is the answer to naval superiority: bounce to Slavery/Theocracy and WHIP battleships everywhere. How to deal with Emancipation anger? The culture slider, plus using my espionage muscle to spy-bonk France and Russia out of Emancipation. (How exactly does that work, logically? A foreign citizen, within two to five years, gets the entire country to elect a political party in favor of slavery? Huh?)
Anyway, Babylon's main invasion stack (seen above) was about 30 cavalry. I piled all my drafted infantry into the city and it held.
But Babylon surprised me elsewhere! Hammurabi used amphibious attacks to snag two undefended (like longbows) coastal cities! I didn't think the AI did that! Recapturing them was no problem with some tanks by Coventry playing zone defense, but I did lose a couple national wonders. Had to rebuild them later.
Cities close to the action built navy and drafted infantry. Faraway cities built about a dozen Airships that proved amazingly helpful for naval support. They really help tilt the odds in battleship fights, and running recon with them is key to planning naval tactics.
And now I noticed one Babylon island city within easy reach, so that transports can reach the city directly from one of my own. This should force Babylon into our requisite white peace treaty.
Whacked another island city, but H still wouldn't talk. Now I was finally winning the naval war.
I continued on to Sirian Doctrine a curiously underdefended coastal city. Just one infantry? Must have had a bunch of units on the transports. Then when Babylon re-founded a new city on the spot and sailed five more transports into it, I did it again.
In fact, before Hammurabi would lift the no-talk embargo, I actually got as far as capturing his CAPITAL along with another city. They were also lightly defended, two or three infantry each, no marines or tanks. Nippur has the Confucian shrine. Babylon holds Rock N Roll and CRISTO REDENTOR! Time to make peace after this.
But there's a problem. I've made a tactical blunder. Do you see it?
If I sign peace now, my entire invasion stack will be bumped into Babylon city and STUCK there! I'd have to build all new units for my French attack. No time to do that, Rheims is at 55000 culture.
I had to wait a turn - letting the cities get recaptured, I couldn't defend them against railroads. Then recapture the cities, Babylon *first* and move the transports out to Nippur second. At long last, peace broke out.