The thesis purports to assess the United Nations Security Council (UNSC) in maintaining international peace and security and the International Criminal Court (ICC) in prosecuting individuals who have committed severe violations of international humanitarian law (IHL) and international law, during humanitarian and counter-terrorism operations. The thesis endeavours to highlight the failures of both institutions, firstly, the UNSC being unable to fulfil its institutional mandate, which is mainly attributed to the abuse of veto privileges granted to the five permanent members (P5). This has effectively allowed individuals from the militaries of the P5 and their allies elude criminal liability, promoting a culture of impunity. The UNSC’s failure to prevent P5 members use of unauthorised military force in pursuing counter-terrorism operations and interpose expeditiously in humanitarian crises, have also contributed to the erosion of the institutions’ legitimacy, which is further perpetuated by the USA’s continued ‘War on Terror’ doctrine after the 9/11 terrorist attacks. Secondly, the ICC’s inability to prosecute individuals for crimes under the Rome Statute will also be highlighted as the principle of complementarity and the court’s inability to enforce arrest warrants are significant factors contributing to the institutions inability to administer international criminal justice. The thesis draws upon practical examples to substantiate the failures of both institutions by referring to the conflicts in: Afghanistan, Iraq, Palestine, Syria and Libya. Before concluding the UNSC and the ICC have become futile, the thesis will then make recommendations for reform and propose a novel solution to restore legitimacy back to both institutions.