This article aims to contribute to the current academic debate concerning the responsibility to protect (R2P) doctrine, by offering a critical perspective of the legal grounds and effectiveness of this doctrine. In the first part of this article, the emergence and evolution of the doctrine is examined, through the analysis of reports and documents written under the auspices of the United Nations. According to this early perspective, R2P was intended to act as an 'obligation' for states, as members of a new 'human-centred' international community. However, this ambitious vision was soon at odds with reality. The second part of this article is focused on a tentative deconstruction of R2P, by analysing the definition of 'responsibility' and the weaknesses of the doctrine as a whole. While the first and the second pillars do not pose particular concerns relating to their accordance with international law-even if their content does not add much in respect of the existent international instruments promoting or protecting human rights-the third pillar is very vague and unclear in terms of legitimate legal basis and effectiveness. Therefore, the third part of this article underlines the inconsistencies of the third pillar, by criticising its application within the context of the UN. The aim of this section is to determine whether or not the recent references to R2P doctrine contained in Security Council resolutions since 2006 can contribute to the consolidation of the R2P principle in practice. In concluding, a tentative approach to finding new legal grounds for R2P is presented. This restyling of an old-fashioned theory on intervention in case of erga omnes obligations is aimed at reinvigorating the doctrine in order to achieve the primary objective to reconcile universal legitimacy and effectiveness in defence of human rights.