Peace Keeping Force...

[C Chulainn]

Has anyone else found themselves doing this?
On a large continent, I'm the biggest power, situated between Egypt (reduced to 3 cities along time ago) in the south and Germany and Japan in the north.
I had pacts with both Egypt and Japan, only to see them declare war on each other. Not having a common border, the formidable Japanese army started moving through my territory to get at Egypt. If I'd demanded they withdraw, they'd have declared war on me too; if they'd got through I'd have had to declare war on them...
The only thing to do was create a peace keeping force out of my obsolete units, lining them all up along the border with Egypt and making it impossible for the two sides to fight on land. I built a couple of privateers and sank any Japanese unit that threatened to sail into Egyptian waters.
Eventually, the two sides just gave up!
Hopefully my pact with Egypt will expire, preventing me from being dragged into a costly war.

[Zanzin]

Lol, that's an interesting situation.

I've found that creating physical borders out of units is one of the best ways to stop the AI from advancing, given you're not at war with them

[optimus2861]

This trick is especially useful for blocking AI settlers from getting to those tiny patches of land that aren't contained within your borders. Doesn't always work perfect: while I was blocking a French settler from getting to a field of plains with a wheat-bonus last night, AI decided, "OK, I'll just build right here then" and plonked down a city in the forest adjacent to it .

[Harovan]

I usually take my first captured workers to line up and block these settler-spearman-shuttles. They are useless for most early work anyway (for what do I need a unit that builds a road on grassland in 6 turns and cleans jungle in 48?) Works quite effective, and if the AI declares war and kills 1 or 2 of them, oh well, who cares?

In a recent game I got bored to block the AI directing to a small patch of land at my border and sent myself a settler there. The city seemed to be totally misplaced, stole room from 2 other cities, and produced nothing useful. Later a new iron resource was discovered nearby, and a former jungle tile gave a coal, I built the iron works inside and the FP in an adjacent city and I had a kickass 120 shield city in the late industrial age. The coal later disappeared, but the productivity remained.

Now I am wondering if the AI cheats and knows earlier where those resources appear...

[The Hun]

Great foresight and awareness! My head is usually buried so much in my own diplomacy that I forget to mind the diplomacy of others.

[The Eliminator]

I've had about a half dozen games or so where I've managed to block off the bottleneck. Every single time, the other civ has declared war on me. First you see a settler or two bouncing around you, then next thing you see is a pile of warriors/archers/whatever - and then the inevitable sneak attack. The physical border has yet to work for me.