However, Islam as a vehicle of Indonesian nationalism had gradually waned in the face of the emergence of secular nationalism and more radical political thoughts such as communism. The inner struggle among Sarekat Islam between the reformists and the traditionalists had also contributed to its decline. This created a vacuum within the Muslim community for the leadership role, filled by civil society organizations such as Muhammadiyah, NU, more puritanical PERSIS, and Al-Irshad Al-Islamiya. These organizations upheld non-political position and concentrated on the social reforms and proselytization. This trend persisted during the Japanese occupation as well, whose occupational administration took the ambivalent stance toward Islam. Islam was considered both as a potential friend against the Western imperialism and a potential foe against their vision of Greater East Asia Co-Prosperity Sphere.