pacifism

Concise Oxford English Dictionary © 2008 Oxford University Press:
pacifism/ˈpasɪfɪzəm/

▶noun the belief that disputes should be settled by peaceful means and that war and violence are unjustifiable.

– derivatives
pacifist noun & adjective.

– origin early 20th cent.: from Fr. pacifisme, from pacifier ‘pacify’.