Aust's Modern Treaty Law and Practice

Non-legally binding instruments do not constitute treaties but they are widely used by states and international organisations as a form of political commitment. They have various titles, the most common of which is memorandum of understanding, although some states use this title also for treaties with a certain subject matter. In the multilateral context, non-binding instruments are often used for plans of action, guidelines and other forms of standard setting. To ensure that an instrument is non-legally binding, care must be taken in the drafting to evidence that intention, including use of the right terminology. An examination of state practice reveals broadly similar principles. Why do states and international organisations use non-legally binding instruments in preference to treaties? Reasons include confidentiality, lack of formality, and ease of amendment and termination. But there are risks, including possible lack of respect for commitments and lack of care in drafting. Non-legally binding instruments, both bilateral and multilateral instruments, may in some contexts be regarded as a form of soft law. They may also exceptionally give rise to estoppel. Non-legally binding instruments may also be evidence of a state’s decision or policy in the context of judicial review by domestic courts.