Urgh - I searched for this thread to understand what it is that I did wrong to get this large penalty across ALL civs in my current game.
Rome - early leader, aggressive bastards.. after scouting my borders and amassing a huge army he waged a war on me early game. I wipe his army out, we peace, he rebuilds his army and comes at me again. I wipe it out again, and refuse peace.
I march south, raze his closest city in spite, and continue on to capture his capital Rome as my own. We peace, and I leave him with his remaining 3 cities in a fairly crippled state.
Years go by, and the bulk of my army remains along the borders of Rome City and his territory because I don't trust him, as he has slowly rebuilt his civ and his army.. I have a defensive pact with Brazil, who is also bordering Rome. Rome asks me about my troups; I am not interested in declaring war on him, but I certainly want to deter him from attacking me.
Years go by, and, feeling a little evil towards Rome still, I pay him to declare war on Brazil, which he does. My defensive pact with Brazil kicks in, and the entire world has the negative diplomacy penalty with me for breaking my promise. Technically speaking, I merely came to the aid of Brazil.. they don't have to know it was my cash that started the war!
Anyway, the thread has been a good read. I've learnt a bit from it, and will be more prepared in future to take care with my troup placements. I cannot really complain about my diplomacy situation.. I've had it in for Rome since his first attack.
My conclusions are;
1) 50 turns is a bit too long, would rather see it as 30
2) I wish we could call the AI out on their troup amassing
3) A warning before the diplomacy option could be handy to avoid any 'accidental' troup movements triggering it. Something like "Ghandi is showing concern at your troup movements", and if your troups are still there next turn, or move out and return within 30-50 turns, then trigger the diplomacy options for war/placate as it would have.