Ok, so here's a little something I find fun. Not necessarily perfectly efficient, but fun:
If you have a continent to yourself and any kind of tech or production lead, you can probably prevent from ever having to defend your own cities. The general idea is to destroy all AI port cities, and never let them build any useful navy. It works because:
1)The AI prefers perfect city spacing to perfect city location, this means that a lot of the coast will be occupied with non-port cities, and only a few will actually be on the ocean front. This leaves you with only a few cities per nation to destroy.
2)After razing one or two cities, the AI will normally accept peace (at least in my experience).
3)A rebuilt city will take a
long time before it can produce a carrier or BB.
4)The expense of maintaining 4 or 5 strike forces is less than defending against a possible large-scale assault.
5)Whipping the AI using hit-and-run tactics is more fun than building up artillery and waiting for them to invade.
The major downfall is that you can't trade during peacetime for things that require an AI port to connect to it's capital. Shucks.
Naturally this will be less easy or useful on the larger maps, but on standard or smaller I have enjoyed it
.
