ABSTRACT
Liberal internationalism, as a constellation of ideas, ideologies, and movements, came to the fore in Europe and the United States in the late nineteenth century, where it flourished until the mid-1940s. This chapter explores liberal internationalism in both its ideational and institutional forms, focusing particularly on its prescriptions for peace and its connections and overlaps with pacifism. It highlights proposals for an international police force as a contentious issue between muscular and pacifist strands of liberal internationalism. British liberal internationalist thinking developed into a "new liberal internationalism" pioneered by a small coterie of intellectuals writing in the first two decades of the twentieth century. In the United States the foundations of liberal internationalism date back to the turn of the century, when internationalists and their organizations—such as Hamilton Holt's World Federation League (1872–1951)—called for greater international organization.
