This chapter is in French with an English summary. Notwithstanding the salutary character of the obligation of non-recognition, several authors continue to doubt its existence. Thus, the most important French legal literature on recognition constitutes a fierce case against this obligation characterized as "fanciful" having gone "bankrupt". These criticisms seem to be unfounded and unjust. This chapter first examines in a systematic fashion the different arguments denying the obligation of non-recognition, in order to show that it is not a legal phantom but indeed forms part and parcel of general international law. The obligation of non-recognition constitutes the minimum sanction in a legal order which cannot, without destroying itself, accept its capitulation in the face of a fait accompli. The chapter then attempts to clarify the content of the obligation of non-recognition in order to show that it is not symbolic but implies actual obligations on States.