I'm on the prince difficulty with standard amounts of peeps playing on an earth type map.  The civs are/were Jap,Turks,Greece,Rome,Arabia,Siam,some other guy, me.  Anyhow i tried manipulating everyone to fight wars against each other.  This worked well as the japs took istanbul.  i thought that since rome and greece hated japan  and had just declared war they'd be ok with my war against them. guess not. either way we knock out japan and then arabia and alexander declares war on me. i take one city from Arabia and force a treaty, i took athens and sparta and destroyed the greeks..  later Arabia who were in africa takes out their neighbor Siam.  now their all hostile towards me except that other guy i havent met, and they're all willing to wage war on me only 2 cities can produce or i go to -30 happiness. and since if they declare war on me i can't maintain a 2 front war. what can i do?

Its an issue the game has - being a warmonger, even if you helped an ally is a bad thing in the minds of other civs.  Hopefully that will be addressed in a patch, as Civ 4 handled that more realistically.

If you want game with good diplomacy play Napoleon: Total War. At least there you can see why everyone hates you :P

The Japanese. Not Japs.

" Its an issue the game has - being a warmonger, even if you helped an ally is a bad thing in the minds of other civs.  Hopefully that will be addressed in a patch, as Civ 4 handled that more realistically. "

I'm happy to report, that even though i went though 2 wars with the exact same people(arabia/rome), technically lost the first one to arabia but beat rome on both accounts, bankruptcy, -20 unhappiness,long ass shots. France(I) has conquered Rome,Mecca, the rest of the ottomans, and found  Babylon some 20 turns away and took that too.  and it was pretty epic. city states rock.