I sure am having a lot of sabotage done against me. Poisoned water is particularly bad. I can't find anything in the civilopedia about it. Is there a way to defend against sabotage?

Years ago when I played Civ II and III, I used to be able to search these forums for answers. The search function doesn't seem to work as well as back then.

increase the Espionage spending against the guilty AI (is Sitting Bull nearby by anychance?) to make the missions more expensive.

Placing spies in you cities also increases the chance of catching the enermy spy.

yes, Sitting Bull :-)

thanks for the reply

Run counter espionage missions every 10 turns too.

EDIT: Great minds think alike, whilst fools seldom differ ;)

use the counterespionage mission

turn up your espionage slider, run counter espionage missions, close your borders with Bull, and have a spy in the affected city. which would have the combined effect of increasing the cost of running espionage missions, and increasing the likely hood of the spy getting caught.

And once you build Security Bureaus in your Spy-protected cities, you can move those spys to key resources to increase your chances of intercepting enemy spies, or into other countries to run counterespionage or other missions.

I play at Prince/Epic/Standard/Tectonics, and I usually have to run the espionage slider at 10% minimum to generate enough passive espionage points to get the demographics and research view. Depending on how much you want to micromanage, you can sometimes tell who the guilty party is by noting who spent espionage points last turn. That's a lot of micro, though.