two-way street
mutually
bilateral
go halves
two-way
liaise
corespective
equalism
intercession
impartial
polder model
arbitrate
mediate
intermediate
intercede
equally
panarchy
corresponsive
shareout
constructive force
cooperative
six of one, half a dozen of the other
cartel
equifacial
dialogue
deal
dialog
synallagmatic
backscratch
tripartisanship
win-win
level set
it takes two to tango
Switzerland
equivalence
arm's length principle
similiter
fairly
equidistribute
cat and mouse
concurrent
omniparity
made for each other
takeover
good faith
bilaterally
mediation
trade
evenhandedly
swop
swap
seat at the table
cross-party
covenant
barter
fair
bipartisanship
law of action and reaction
requirements contract
peel
Newton's third law of motion
agreeingly
interresponsibility
Newton's third law
reciprocal
equivalent
both-sides
without fear or favour
third law of motion
multiparty
will contract
isocracy
entente cordiale
equality
inter partes
uniparty
conditional agreement
interplaying
concert
eunomy
match
trench mentality
even-stevens
go for
sweetheart deal
mutual
high road
according
modus vivendi
common
correlate
cooperability