Offensive force is utterly immoral, condemned by all men of good will and prohibited by Jesus/God. Nothing "instituted among men" can make that right.
All such warring organizations will ultimately self destruct, or atrophy as they are replaced by moral systems. I consider such organizations the fiefdoms of satan, and believe scripture teaches that God himself will ultimately destroy any holdouts.
Defensive force is moral, but optional, depending on the circumstances and choice of the individual or group being aggressed against.
"Anarchy" literally means "no rulers," a situation far more prone to peace than a society oppressed by control freaks who believe they have a right to rule their neighbors.