Introduction In the United States, the Student Volunteer Movement for Foreign Missions was organized at the end of the 19th century, and foreign missions saw a peak in the 1910s. After WWI, however, people did not show much concern for foreign missions. Diminishing interest in religion can be pointed to, in the first instance. The absolute truth of the Bible had been challenged by the Higher Criticism and the theory of evolution. Furthermore, the spread of entertainment, including movies and radio in the 1920s, led to a decline in the number of churchgoers. The moral certitude of Christianity, which had been the basis of foreign missions, was weakened because of the war between Christian countries. Cultural anthropology, a new academic field, had moreover suggested that Christianity could not be grafted easily onto a heathen culture since religion was based on the unique history of each country. Thus, it seemed that the compelling causes to promote foreign missions had not been appreciated. In practical terms, donations for foreign missions had decreased and every foreign missionary organization faced financial difficulties in the latter half of the 1920s, this difficulty worsening after the Great Depression.1 From the 1920s to the 1930s, the relationship between Christianity and other religions, the substance of foreign missionary projects, and the number and quality of missionaries were re-examined in the Protestant foreign missions.2 In the area of missions for women, for example, the paternalistic attempt to achieve improvement in the status of heathen women was abandoned after WWI, and a new missiology of World Friendship was adopted. This missiology considered it ideal to encourage friendships with heathen women and work together on an equal footing for peace and justice.3 Various Protestant denominations jointly conducted a large-scale survey in 1930 to redefine foreign missions, and the result was published as Re-thinking Missions (1932). After denying the absolutism and superiority of Christianity, this book drew a sharp line between the mission to convert people and the service-oriented activities such as education and medical care, and suggested that the latter should be regarded as more significant. The book called upon missionaries to act as ambassadors, i.e. while being invincible Christians themselves and hoping for others to become Christians, they should not dare to force others to convert. It also pointed out the ill effects and inefficiency of promoting foreign missions through respective denominations.4 Considering the criticism of foreign missions and the emergence of a new