In Israel, the Jewish religion, which is unique among world religions in the primacy it accords to filiation rather than belief as a criterion of belonging, operates as a formal criterion of citizenship, but in substance different ways of being Jewish are expressed in different political forces which in turn struggle for control of the state's religious orientation. This political struggle leads the state to favour ultra-Orthodox observance and criteria of belonging, even though that is a minority strand in the country itself and even more so outside. Religious interests and ideologies have found substantial niches in the legal system, in education, in the army and in the West Bank settlements, by exploiting the state's corporatist character, leading to a type of multiculturalism in which the once-secular centre has been seriously eroded.