Uncertainty surrounding the legal effects of soft law
Section 2.3 was a brief overview of soft law’s functions and potential effects. As such, the cases mentioned are solely a few examples of precedents within the UN human rights system, where provisions contained in soft law instruments have evolved to acquire greater legal value beyond their adoption as part of non-binding resolutions or declarations. But such evolution is by no means linear or systematic. This highlights a core issue with soft law instruments from the standpoint of state practice: the uncertainty regarding the potential value of its provisions, as to whether or not it might eventually give rise to legal obligations.
Indeed, it is important to recall that there is no agreement, either in theory or in practice, on the actual effects of soft law instruments. This is partly due to the variety of instruments categorized as ‘soft’,  and partly because soft law’s effects can be changing as distinct instruments evolve in practice. This process is not formalized in any specific way; rather, it happens organically.48 Many factors can come into play in determining what course an instrument will follow, and that can partially be independent of the will or consent of states parties who adopted the instrument in the first place (i.e. it could be the result of a concerted effort from states who were initially parties to the soft instrument and consent to work towards a binding framework on the same issue,49 but it could also happen through the evolution of organizational practices within the UN,5° the action of non-state actors and lobby groups,51 or through court proceedings,52 without necessarily involving an additional expression of consent from initial states parties).
Still, the potential harder effects of soft law have been confirmed over time by precedents such as the cases mentioned here. Such precedents and interpretations are likely to fuel uncertainty and apprehension, as states parties who are not totally comfortable with the content of new soft law instruments presented for adoption can no longer rely on the ‘soft’ status of the instrument to deny it all potential legal effects.53 There is no way to know with absolute certainty, at the adoption stage, which form a soft law instrument is likely to take in the future, and what kind of legal obligations could arise from it. But it is no longer possible to simply assume that the provisions adopted as part of a soft, non-binding instrument will remain as such. This chapter argues that this does not go unnoticed and is increasingly acknowledged in state practice, in ways that are likely to affect the way states approach commitment to new soft law instruments in the future. This becomes clear when examining the adoption process of one recent UNGA declaration, the UNDRIP, and the unusual state behaviour it triggered.
J. Gersen, ‘Soft Law: Lessons from Congressional Practice’, Stanford Law Review vol. 61 (2008): 573. E.g. there is no formal basis in the UN Charter (or in the UNGA Rules of Procedure) providing for special resolutions to be adopted as ‘declarations’. UN, Rules of Procedure of the General Assembly, A/ 520/Rev. 17,
- 49 Considering that soft law can be a tool building ‘compromise over time’. Abbott and Snidal
- (2000): 446.
- 5° See e.g.: J. E. Alvarez, International Organizations as Law-Makers (Oxford: Oxford University Press, 2005); A. E. Boyle and C. M. Chinkin, The Making of International Law (Oxford: Oxford University Press, 2007).
- 51 M. E Keck and K. Sikkink, Activists beyond Borders: Advocacy Networks in International Politics (New York: Cornell University Press, 1998); Non-state Actors and Human Rights, ed. P. Alston (Oxford: Oxford University Press, 2005); Non-state Actor Dynamics in International Law: From Law- Takers to Law-Makers, ed. M. Noortmann and C. Ryngaert (Aldershot: Ashgate, 2010); D. Hollis, ‘Why State Consent Still Matters: Non-State Actors, Treaties, and the Changing Sources of International Law’, Berkeley Journal of International Law vol. 23 (2005): 1.
- 52 See e.g.: C. J. Tams and J. Sloan, The Development of International Law by the International Court of Justice (Oxford: Oxford University Press, 2014); K. J. Alter, The New Terrain of International Law: Courts, Politics, Rights (Princeton: Princeton University Press, 2014).
- 53 Voyaiakis raises a similar point in respect to the intrinsic role of voting behaviour in the formation of CIL. Voyiakis (2011): 220—1. This chapter considers that it is equally valuable for other paths through which soft law could ‘harden’.
-  As Gruchalla-Wesierski, Chinkin, and many contributors to this volume have pointed out, theterm soft law can be used to refer to many different concepts, e.g. legal soft law, non-legal soft law;Gruchalla-Wesierski (1984); C. M. Chinkin, ‘The Challenge of Soft Law: Development and Changein International Law’, International and Comparative Law Quarterly vol. 38 (1989): 850. Even whenfocusing on soft law instruments, the concept will refer to a variety of instruments adopted throughdifferent instances, to fulfil different functions (norm-creating or norm-filling), and used by differentactors for various purposes.
-  The creation of a soft law instrument is often not regulated by formal procedural requirements.This is considered by Posner and Gersen as a constitutive dimension of its soft character. E. Posner and