to devote the maximum available resources for the realisation of economic, social and cultural rights; and obligations of international assistance and cooperation. Second, they have addressed the links between the obligation to mobilise resources with several other obligations, such as the obligation to progressively improve conditions; prohibition of taking deliberately retrogressive measures; the obligation to accord a degree of priority to human rights in the allocation of resources; the obligation to monitor the realisation of human rights, and to devise strategies and programmes for their implementation; and the obligation to ensure the minimum core level of economic, social and cultural rights. These related obligations shape part of the content of the obligation to mobilise resources. For example, as part of the obligation to progressively realise economic, social and cultural rights, states should ‘identify the resources available to meet the objectives and the most cost-effective way of using them’. In line with the principle of non-retrogression, a state making cuts in social spending has the burden of proving that the retrogressive measure was the least human rights-damaging alternative. In order to fulfil its minimum core obligations, a state must demonstrate that every effort has been made to use all resources that are at its disposal to satisfy the minimum essential level of rights as a matter of priority. Among these human rights obligations, states should regularly monitor the realisation of human rights, including assessments as to whether the maximum available resources have been used to progressively achieve the full realisation of economic, social and cultural rights. Third, from the work of human rights monitoring bodies, it is evident that core human rights principles should guide the implementation of the obligation to mobilise resources. The principle of non-discrimination shapes not only the ultimate outcome, but also the process of resource mobilisation. On the one hand, resource mobilisation should eventually lead to reduced economic, social and geographical disparities, and provide for wealth redistribution in order to redress systemic discrimination and spur progress towards substantive equality. On the other hand, ‘the rights to equality and non-discrimination should be respected in all revenue-raising policies. Thus, any action, or omission by the state in this area must not discriminate, either directly or indirectly, against any individual or group or perpetuate discrimination and inequality.’ Other principles, such as transparency, participation and accountability, are also often referred to by human rights monitoring bodies, although in a general manner, requiring more attention in the future. This is particularly the case regarding the principles of sustainability, efficiency, effectiveness and cooperation that some human rights monitoring bodies have linked to the obligation to mobilise resource, although without fully exploring their content and potential. While the core features and principles of aforementioned international human rights law assist in the definition and implementation of the obligation to mobilise resources, uncertainties remain as to the legal basis of the obligation to mobilise resources, and the scope and content of the principles that should guide resource mobilisation. Human rights monitoring bodies should do more to clarify some components of the obligation to mobilise resources and develop assessment methodologies to monitor compliance by states. The lack of more precise legal concepts poses several challenges to human rights monitoring bodies seeking to assess compliance with the obligation to mobilise resources. How can they evaluate state responses in terms of compliance with the obligation to mobilise resources if the legal foundation of such obligations are themselves not clear? What are the December 2017   The Obligation to Mobilise Resources: Bridging Human Rights, Sustainable Development Goals, and Economic and Fiscal Policies 11