I'm sort of exploring where pacifism and socialism come into conflict. How do you reconcile a passionate rejection of might and violence with an attitude of "nil paseran" - "none shall pass" - in the face of fascism?

I'm sort of exploring where pacifism and socialism come into conflict. How do you reconcile a passionate rejection of might and violence with an attitude of "nil paseran" - "none shall pass" - in the face of fascism?