Spies in Road to War

[mscheaf]

I have been trying out Road to War recently but I don't understand how the spies work. I have used spies in other BTS games, and I am most used to Rhyes and Fall. But in this mod it seems when I am not at war with someone I cannot do any espionage missions even if I have the points. I move my spy to a city and then wait a turn and the perform esp mission button is still greyed out. If I hover over it it says "Cannot perform espionage mission, visible to <leader of civ I am trying to spy on>." When I am at war with someone, my spies cannot go into their cities at all, that is if I can even get to them without being immediately captured. What am I doing wrong?