Forthcoming in the Max Planck Yearbook of United Nations Law (27) Some states, on the other hand, have been dissatisfied with the (im)balance between codification and progressive development. As certain delegations observed, the Commission went ‘far beyond’ existing norms on the topic, especially where state practice remained inchoate. Others pointed to the possible mismatches between the regime established by the draft articles and already existing frameworks on the expulsion of aliens, which could ‘hamper relevant international cooperation and […] result in impunity of criminals’.138 Subjacent to these reactions are the political sensitivities raised by the international regulation of migration, an area where states have increasingly conflicting views. 139 This is well illustrated by the more recent debates on the 2019 Draft Articles on Crimes Against Humanity,140 which expressly provide for an absolute prohibition on refoulement. According to Draft Art. 5, states would be barred from expelling, returning, surrendering, or extraditing an individual where ‘there are substantial grounds for believing that he or she would be in danger of being subjected to a crime against humanity’.141 An additional paragraph details some of the positive obligations deduced from the duty of non-return, including an obligation to conduct a risk assessment. While the provision simply replicates a formula adopted by various human rights treaties since at least the 1980s,142 some states have been particularly exasperated by the lack of security exceptions 143 – showing yet again their hesitancy in This issue was raised by China. See UNGA, ‘Summary Record of the 20th Meeting: 6th Committee’ 69th Session, (10 November 2014) UN Doc. A/C.6/69/SR.20, at 5. 139 As Sean Murphy rightly notes the ‘central difficulty with [this] project, namely, that it attempts to codify a series of rules in an area where states already have long-standing, detailed, divergent, and ever-changing national laws and regulations that touch upon sensitive national security concerns’; see S.D. Murphy, ‘The Expulsion of Aliens (Revisited) and Other Topics: The Sixty-Sixth Session of the International Law Commission’ (2015) 109 American Journal of International Law 125-145, at 130. 140 UN ILC, ‘Draft Articles on Prevention and Punishment of Crimes against Humanity’ in Yearbook of the International Law Commission 2019, vol. II (Part Two) UN Doc. A/CN.4/SER.A/2019/Add.l. 141 Ibid., at Art. 5(2). 142 For instance, Art. 3 of the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment (adopted 10 December 1984, entered into force 26 June 1987) 1465 UNTS 85. 143 Especially by the United States, the UK, Jordan, Iran, and China. See e.g., UNGA, ‘Summary Record of the 19th Meeting’ (20 November 2017) UN Doc. A/C.6/72/SR.19, at 2–3, 9–10, 15. 138 35 Electronic copy available at: https://ssrn.com/abstract=4816199