What boots it at one gate to make defence, And at another to let in the foe?

Never interrupt your enemy when he is making a mistake.

I think you're battling common enemies that a lot of other communities are. It's occurring in a lot of Midwest communities.

Forgive your enemies, but never forget their names

Wee commonly say of a prodigall man that hee is no man's foe but his owne.

Enemies are necessary for the wheels of the U.S. military machine to turn.