This article first situates the Responsibility to Protect (RtoP) in relation to humanitarianism and the 'politics of humanity' through which common humanity is understood, negotiated and defended in response to 'crises of humanity'. It outlines the humanitarian negotiations at stake, connected with the mass atrocity crimes within the RtoP's remit. Second, it argues that, like other claims made 'in the name of humanity', the power relations implicit in attempts to create, delimit and safeguard 'humanitarian space' need to be unpacked. Third, it assesses the RtoP's potential to become a success with regard to the fulfilment of the humanitarian aspirations it represents, concluding that its inability to escape its political nature should be seen as a strength, not a weakness, but that the relationship between a humanitarian project like the RtoP and the notion of humanity will always be a dynamic, unpredictable and risky one, dependent on judicious political judgement.