There have been some attempts to overcome this difficulty.159 From the point of view of international law, two considerations seem relevant. First, since the 1970s, it has been agreed that rich countries should dedicate 0.7 per cent of their gross national income to official development assistance.160 This joint commitment has been re-affirmed in subsequent international declarations,161 and the Committee on Economic, Social and Cultural Rights has taken it as a benchmark to define the obligation of international assistance. The rise of the notion of common but differentiated responsibilities among States,162 and various examples of negotiated systems of burden-sharing established to address challenges or duties of a global character,163 confirms that international law is moving towards the recognition of differentiated duties, depending on the capacity and resources of each State.164 Only a handful of countries are in fact delivering on this commitment, however,165 and even when progress is made towards reaching the 0.7 per cent target, how that figure is calculated continues to be controversial.166 Secondly, where a result obtains which may engage the responsibility of one State (for instance, a famine develops due to the lack of international aid, although provision of support by that State might have averted the disaster), such responsibility is not diminished by the mere fact that the result might have been avoided if other States had adopted a different conduct.167 Indeed, any other reading would 159 See, inter alia, Sakiko Fukuda-Parr, "Millennium Development Goal 8: Indicators for International Human Rights Obligations", Human Rights Quarterly, vol. 28(4) (2006): 966-997; Margot E. Salomon Global Responsibility for Human Rights: World Poverty and the Development of International Law (Oxford University Press, 2007), at 193; Margot E. Salomon, ‘Deprivation, Causation, and the Law of International Cooperation’ in Malcolm Langford, Martin Scheinin, Willem van Genugten and Wouter Vandenhole (eds), Global Justice, State Duties: The Extraterritorial Scope of Economic, Social and Cultural Rights in International Law (Cambridge University Press, 2012): 259-297. 160 General Assembly, International Development Strategy for the Second United Nations Development Decade, GA Res. 2626, UN GAOR (Twenty-fifth session, 1970) (A/RES/25/2626 (XXV)), at 43 (1970) ("Each economically advanced country will progressively increase its official development assistance to the developing countries and will exert its best efforts to reach a minimum net amount of 0.7 percent of its gross national product at market prices by the middle of the decade"). 161 The 0.7 per cent target was mentioned in the ‘Monterrey Consensus on Financing for Development’ (22 March 2002), UN Doc. A/AC.257/32, at 42 (2002); in the ‘Doha Declaration on Financing for Development: Outcome Document of the Follow-up International Conference on Financing for Development to Review Implementation of the Monterrey Consensus’, annexed to GA Res. 63/239, UN Doc. A/RES/63/239, at 43 (2009); and most recently in the Addis Ababa Action Agenda adopted at the Third International Conference on Financing for Development (Addis Ababa, Ethiopia, 13–16 July 2015) and endorsed by the General Assembly in its resolution 69/313 of 27 July 2015, at para. 51. 162 For example, United Nations Framework Convention on Climate Change (1992, in force on 21 March 1994) (1994 (1771 UNTS 107; 31 ILM 851 (1992)), Art. 3. 163 See, for instance, IDA’s Long-Term Financing Capacity (International Development Association Resource Mobilization, February 2007); or The Global Fund to Fight Aids, Tuberculosis and Malaria, Third Replenishment (2011-2013) (The Global Fund, March 2010). 164 See more generally Lavanya Rajamani, Differential Treatment in International Environmental Law (Oxford: Oxford Univ. Press, 2006); and David Magraw, "Legal Treatment of Developing Countries: Differential, Contextual, and Absolute Norms", Colorado Journal of International Environmental Law and Policy, vol. 1(1) (1990): 69-99. 165 For instance, an October 2016 report from Concord and AidWatch lamented that "only five EU countries met their [0.7 per cent] target in 2015": these were Luxembourg, Sweden, Denmark, the Netherlands and the United Kingdom. See Concord / AidWatch Report 2016, This Is Not Enough, available at: http://library.concordeurope.org/record/1834/files/DEEEP-REPORT-2016-081.pdf (last consulted on 20 Dec. 2016), at 6. In the Addis Ababa Action Agenda, the Governments expressed their "concern that many countries still fall short of their ODA commitments and we reiterate that the fulfilment of all ODA commitments remains crucial. ODA providers reaffirm their respective ODA commitments, including the commitment by many developed countries to achieve the target of 0.7 per cent of ODA/GNI and 0.15 to 0.20 per cent of ODA/GNI to least developed countries" (Outcome document cited above, para. 51). 166 For instance, it has been shown that rich countries sometimes include in the calculation of their ODA costs of the hosting of refugees or student grants : the Concord / AidWatch report referred to in the previous footnote notes that in 2015, 17% of the aid reported by EU countries "did not reflect a real transfer of resources to developing countries, because it went to “indonor” refugee spending, debt relief, student costs, tied aid and interest payments. Some EU member states increased their reported aid almost entirely through spending on refugees in their own countries, thereby becoming their own top beneficiaries" (Concord / AidWatch Report 2016, This Is Not Enough, cited above, at 6). 167 In the Bosnian Genocide Case, the International Court of Justice noted that, in order to find Serbia responsible for not having prevented acts of genocide : "...it is irrelevant whether the State whose responsibility is in issue claims, or even proves, that even if it had employed all means reasonably at its disposal, they would not have sufficed to prevent the commission of genocide. As well as being generally difficult to prove, this is irrelevant to the breach of the obligation of 34