Unilateral Acts of States in Public International Law. By Przemysław Saganek

Abstract

Unlike the law of treaties, which has been codified since the 1960s, the ‘law of unilateral acts’ has featured little regulation and attracted relatively scarce doctrinal attention. In 1996 the International Law Commission (ILC) recognized that the topic of unilateral acts was appropriate for codification and progressive development. However, its work did not result in a comprehensive instrument. At its 58th session in 2006, the ILC adopted ten ‘Guiding Principles applicable to unilateral declarations of states capable of creating legal obligations’ (Guiding Principles).1 As the ILC explained in its introductory remarks, the Guiding Principles were limited to unilateral acts stricto sensu, that is, formal declarations ‘publicly made and manifesting the will to be bound’. The ILC acknowledged that there also existed a ‘very wide spectrum’ of other behaviours that could be designated as unilateral acts, but where there was no intent to produce legal effects through ‘creating, recognizing, safeguarding or modifying rights, obligations or legal situations’. For example, in the Temple of Preah Vihear case the International Court of Justice (ICJ) relied on a number of circumstances and communications between the governments of Cambodia and Thailand, including an expression of gratitude, to conclude that the binding character of a map delimiting the respective territories of these two states had been accepted by Thailand.2 The ILC’s work did not cover such other acts.