Diplomatics

does anybody know how i set up a treaty with another empire that means something like "live peacefully together"?
these non agression options don´t work, cause when another empire initiates combat we both fight each other.
i´m not sure if it´s different in the mutal defense pact, but that also means to aid each other in war.
btw, how does that work with mutal defense pact?? do you get automaticaly go to war with an empire your partner is also in war with?

greetings

Prankowski