Over the years, sovereignty has grown to be accepted as an essential element of international relations. The doctrine of sovereignty is the fundamental organizing principle of contemporary inter-State relations. It is based on the premise of mutual recognition of political independence among states, mutual co-existence, exercise of formal equality in mutual relations and the corresponding principle of non-interference in the domestic affairs of other States. It is sovereignty that confers on a State recognition by other States and gives a State the right to relate with other countries on equal footing irrespective of size. Sovereignty confers on a State the right to enter into diplomatic and trade relations with other States. There is increasing debates surrounding the disparity in the assertion of sovereignty by developing and developed powerful States. Are developing or third world countries truly sovereign? Do they enjoy the same sovereign rights on equal terms with developed states in reality? Are there challenges limiting the plenitude of sovereignty available to weaker countries? This paper discusses sovereignty as an essential element of international diplomacy. It introduces the meaning of the concept of sovereignty, its theories and the concept vis-à-vis international relations. The paper then dealt with the changing paradigm of sovereignty and delves into the various inhibitions of sovereignty, examined the instances of intervention in the domestic affairs of smaller countries by powerful countries, reviews instances of unequal treaties between developing and third world countries. The paper found that what third world countries enjoy is not sovereignty but ‘sovereignty on dictated terms’ of the so-called developed powers. The paper also found that smaller States are not accorded protection from developed countries and that until that is done, the concept of sovereignty will continue to be elusive to smaller nations. The paper recommends that the UN should take proactive steps to give greater recognition and voice to developing countries as well as offering them the platform to assert their sovereignty in line with international law.