Advice with diplomacy; form letters perhaps?

[Gregstrom]

If the opponent has allies, you could perhaps deal with them also. Get them to make overtures on your behalf.

[Digress]

If the opponent has allies, you could perhaps deal with them also. Get them to make overtures on your behalf.

Be careful with that one - sometimes the only thing it results in is their ally sending them a message saying "Lets divide this players empire as follows - I will take provinces A, B and C and you can have the rest ..."