Addams was a major synthesizing figure in the domestic and international peace movements, serving as both a figurehead and leading theoretician; she was influenced especially by Russian novelist Leo Tolstoy and by the pragmatism of philosophers John Dewey and George Herbert Mead. She envisioned democracy, social justice and peace as mutually reinforcing; they all had to advance together to achieve any one. Addams became an anti-war activist from 1899, as part of the anti-imperialist movement that followed the Spanish–American War. Her book "Newer Ideals of Peace" (1907) reshaped the peace movement worldwide to include ideals of social justice. She recruited social justice reformers like Alice Hamilton, Lillian Wald, Florence Kelley, and Emily Greene Balch to join her in the new international women's peace movement after 1914. Addams's work came to fruition after World War I, when major institutional bodies began to link peace with social justice and probe the underlying causes of war and conflict.