The point of BothAnd diplomacy is not for "our kind" to have-it-all, but for all-of-us collectively to cooperate for the common interest. This is supposed to be how democratic politics works, but in practice it too-often becomes "war by other means" **. The BothAnd Blog is a response to the recent polarization of Politics and Religion, calling for more of the scientific attitude of self-doubt. As Benjamin Franklin plead with the deadlocked Continental Congress, each of us should "doubt a little of their own infallibility". Neither Politics, nor Religion, nor Science has access to divine revelation or inerrant information. So moderation & modesty are essential for all inter-faith inter-personal activities.
Wisdom will teach us not to naively assume that the guy on the other side of the table is negotiating in good faith. However, the BA solution is not to immediately switch to bad-faith bargaining, but to continue to play by the rules of a non-zero-sum game. See Game Theory below.

* That Marxist doctrine opposes & reverses the Capitalist position, which is sometimes called the "Matthew principle" as presented by Jesus in the New Testament : Matthew 25:29: "For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken away even that which he hath." So, the rich get richer and the poor get poorer. The reverse of rule by the top-two-percent is sometimes called "the tyranny of the majority", which may be why the two-percenters among the founding fathers did not want to establish the US as a direct democracy.
** "War is the continuation of politics by other means." Clausewitz
Game Theory : https://en.wikipedia.org/wiki/Game_theory