Thanks, Doc!
No problem! Considering how many times this poem's been quoted here at FR with regards to this subject its probably instructive to post it for all to read.
What I get out of the poem is that Frost, in "walk[ing] the line, And set[ing] the wall between us once again" is extolling the virtues of COOPERATIVITY that the wall creates between his neighbor and himself; In other words, the wall leads to their peaceful coexistence.