Certainly there are pacifists among hte non-anarchist left. It would seem a gropu like this would benefit more by advancing the pacifist tactics rather than being commited to anarchism. Or are there no Leninists eg. who are pacifist? I suspect there are non-doctrinaire marxists who are pacifists too and see a role of pacifist tactics and strategy in their own struggles.
Anarcho-Pacifism is considered a tendency all its own I'm pretty sure. I don't see why there can't be a pacifism group for non-anarchists though.
or perhaps an Anti-War group would be nice. seems like it could include all pacifists and people generally despaired with his or her's government involvment in wars around the globe
