This papers's ambition is to question the concept of subsidiarity through its semantic contextualization. Contrary to the official genealogies which attribute the notion to Aristotle and then follow imperturbably the same intermediate stages until the present time (Thomas Aquinas, Althusius, Tocqueville), this work seeks to demonstrate that subsidiarity finds its roots in a recent past, which can be precisely defined. To this end, we trace back two main contexts in the concept's discursive life: 1) subsidiarity as the major component of the social doctrine of the Church; 2) subsidiarity as the major component of the federal governance of Europe. From these reference points, we were able to enlighten a series of structural homologies which, once stylized, share the stigmatization of the same polemical target: the State. Their theoretical exploitation allows then to disentangle some of the main ideological bridges between the Christian and European phobias about the State. At the core of this statophobia are a totalitarian disguise of the State institution and a traumatic experience, that of Nazi Germany, both fields of adversity and historic laboratory against which will appear European federalism.