Nuclear Weapons and Diplomacy

[Petromax]

How exactly does a nuclear attack affect diplomacy? I assume it makes the ais hate or fear you more but I'm wondering what the details are.

 

[Blake00]

I'm not sure on what affect used nukes have on relations either, and funnily enough I have a sort of related question I've been meaning to ask here as well. In one of my scenarios I'm noticing that if I give a AI player 2 nukes he will use one on me, however if I only give him 1 nuke he won't use it. So I'm guessing that the AI believes holding on to at least 1 nuke for "our words are back by nuclear weapons" diplomacy bullying is more critical than using one.