how to expel intruders

[geofelt]

When intruders appear in your city limits, you can ask that they be removed. The AI will usually do this, but often, the intruder reappears the very next turn. This is because the intruder could move outside of your territory using his own movement characteristics. To counter this, you must be patient. If the intruder arrived by ship, you must wait until the ship moves away. If there is a non city space available near the intruder, you must occupy it with one of your units before asking that he be removed.

When the intruder has no avenue of escape, I think he gets removed to his nearest city which might be some distance away.

[Lazarus Plus]

Nice work. I always find it irksome that they could come back a turn later when you could not.

[sethos]

the easiest way: bribe them

[MikeLynch]

Or build throngs of diplomats and put two in every square around the edge of a city whose radius you don't want violated. That way, even if the AI founds a city with an overlapping radius to your own (and I've seen it happen far too often), they can't demand withdrawal b/c diplomats aren't combat units. They won't be able to bribe them, either, if they're stacked. (Or go with Democracy and you cut your number of required diplomats/spies in half.)

In my experience, this does not piss off the AI enough for them to spontaneously attack a member of your "diplomat wall." But my experience is with ToT, and its AI differs from other versions of Civ2, so YMMV.