He became president of the Norwegian League of Nations Society, and although the Scandinavian nations with their traditions of neutrality initially held themselves aloof, his advocacy helped to ensure that Norway became a full member of the League in 1920, and he became one of its three delegates to the League's General Assembly.
Ia menjadi presiden Perhimpunan Liga Bangsa-Bangsa Norwegia, dan meskipun negara-negara Skandinavia dengan tradisi netralitas mereka pada awalnya luntur, dorongannya membantu mewujudkan agar Norwegia menjadi anggota penuh Liga tersebut pada 1920, dan menjadi salah satu dari tiga delegasi untuk Majelis Umum dari Liga tersebut.