At the time of changing politics, environmental crises, and technological developments, the number of people in need of humanitarian assistance is increasing. This assistance is essential to save the lives of millions, alleviate suffering and protect human dignity. However, the assistance supplied is not enough for several reasons. To fulfill the legal mandate of humanitarian aid under international law and reach the Sustainable Development Goals (SDGs), as well as the main aims of humanitarian actors, significant changes in their practices to increase effectiveness and efficiency is needed. On the other side, the sphere of humanitarian relief and military intervention has undergone a relevant change, in sharp contrast to what was before, endorsed by many parts of the International Community. The increase of disasters and crises as well as the fast growth of human rights doctrine have inevitably led to a required redefinition of humanitarian policy and practice: as the humanitarian NGOs have been integrated into policymaking forums, policymakers have increasingly claimed to be guided by ”moral” or ”ethical” humanitarian principles, setting aside the existing legal framework mainly provided by the Charter of United Nations. Indeed, the aim of this paper is to highlight the current weaknesses and strengths of the UN system in this field, in the light of the evolving customary international law, and to provide recommendations to improve it. Throughout this paper, we will provide some facts and figures in the introduction. In chapter 2, we will discuss humanitarian relief, after defining the concept and pointing the main objective, the legal framework under international law and the relation with the Sustainable Development Goals (SDGs) will be covered. It will be followed by a close examination of the Global Governance Structure comprising of the UN System and the cluster approach. Such a huge structure with many actors working for millions of people in need, of course, has lots of strengths as well as weaknesses. Finally, recommendations to increase the effectiveness and efficiency of humanitarian relief will be provided. Chapter 3 is dedicated to a comprehensive analysis of the existing International framework of Humanitarian Intervention, indicating the main Organizations as well as the legal basis involved, with a focus on the United Nations system. In addition, this chapter will discuss the development of a “parallel” Just War Doctrine, against the background of some post-Cold War’s humanitarian crises, here duly reported, which is contributing to shaping a new international approach towards humanitarian interventions and bypasses the black-letter of the Law in place herein. This raises doubts on the effectiveness and efficacy of the existing system that, we will see, displays more weaknesses than strengths, posing interrogatives on the need for a solid and urgent reform of the entire mechanism. Chapter 4 will be covering the post-cold war era of the UNSC and its role transformation, while examining the Iraqi case through testing the elements of the just war theory on this specific case. In chapter 5, we will provide general conclusions drawn up from this paper.