Full pacifism is for monks. Lay people practice limited pacifism; they do not seek conflict but they may defend justice as they see it.
Krishna says to the warrior- “Here is a battle unsought; completely unselfish, for a warrior that is an open door to heaven.”
The limited Ahimsa means that the warrior or the policeman must not use force or bullying for personal ends outside duty.
No-one can expect nations to be pacifist.
A community that is pacifist may be annihilated as were the early undefended Christian monasteries or the great Buddhist Narlanda University in the 16th century India