At some level, every territorial dispute is unique: its geography, its history, and the parties involved. According to this view, international law plays a very limited role or no role at all in territorial disputes. Their resolution invariably depends on political considerations. Gibraltar is no exception. As an enclave on the mainland of one European Union member — Spain — over which another EU member state — the United Kingdom — has exercised control for three hundred years, the competing claims to sovereignty are particularly difficult to disentangle. A unique feature of this particular sovereignty dispute is the revisionary provision in the Treaty of Utrecht and its interaction with the alleged right of Gibraltarians to exercise their right of self-determination.