This Article seeks to assess how the UN system has enforced regimes of non-recognition under international law. Claims by certain communities to constitute states and claims by some states to hold title to certain pieces of territory have met with opposition from various quarters. At times, the United Nations has attempted to organize international non-recognition of such claims. The claim by the state of Indonesia to hold title to East Timor presents a vivid and important example of an attempt to set up a regime of non-recognition by the United Nations. The Article examines how the United Nations addressed the Indonesian claim and inquires whether this amounted to a self-enforcing regime of non-recognition.