This paper is a scholarly contribution to extant literature in international Security and Strategic Studies on Nuclear Non-proliferation and Disarmament in multilateral diplomacy under the aegis the United Nations with special focus on North Korea. The paper chronicles the atomic age, how it all began, its deployment in WW II pacific theatre, the anthropogenic catastrophes it brought about and how it altered the dynamics of modern warfare both in terms of the instruments and the theaters of war, as well as its implication for global peace and security. This study attempt a discursive response to ethical and strategic questions surrounding the nuclear weapon, the global response throughmultilateral diplomacy under the UN, the Nuclear Non-Proliferation Treaty (NPT) and the UN‟s atomic watchdog, the International Atomic Energy Agency (IAEA). This paper adopts qualitative method and theoretically hinges on the Regime, Deterrence and Nuclear Peace Theories. The paper attempts a holistic perspective on the North Korea‟s rise to nuclear power with special focus on the impact of communism on North Korean militarismas well as the efforts of the international diplomatic community to ensure the re-unification of the Koreas since the 1953 Armistice that ceases hostilities without ending the war. The paper highlights the implications of a nuclear North Korea for the Regional Order in the Korean Peninsula and how it undermines the adherence to rule of law in the conducts of international diplomacy. As a Super power and a key player in Post-war diplomacy,the paper spotlights the unilateral and bilateral roles of the United States in the global efforts towards denuclearization Democratic People‟s Republic of North Korea. Findings revealed that the diplomatic bargains and tradeoffs between the Nuclear Weapon States and the non-nuclear weapon states of the NPT had not been complied with by the former (NWSs) which correspondingly are the five permanent members of the United Nations Security Council (the United States, Russian Federation, the People‟s Republic of China, the United Kingdom and France) with respect to their pledge on disarmament in exchange for which the Non-Nuclear Weapon States undertook under the NPT not to acquire a nuclear device. This lack of demonstration of good faith on the part of the five permanent members of the UNSC provided a strong argument for Non-Nuclear Weapons States to acquire the unconventional weapons citing sovereign equality principle of international diplomacy.While nuclear strategy falls short of the Just War Theory (Jus in Bello) its deployment in two Japan‟s cities (Hiroshima and Nagasaki) further elicits posthumously,political, ethical and strategic questions. Nuclear weapons lacked the same status under international law as other non-conventional weapons: biological and chemical weapons in that they are yet to be prohibited globally asthe inchoate Treaty on Treaty on the Prohibition of Nuclear Weapons 2017 is yet to attract the ratification of the Fiftieth Instrument90 days after which it will come into force. The paper Spotlights the international laws on nuclear weapons and the viability of the regimes set aside by the diplomatic community to enforce them. Defectively, the NPT under Article IX created unequal legal status among ratifying states and by that process brought a partial ban on nuclear weapons leaving a legal gap on nuclear weapons in the eye of international law. The denuclearization of North Korea is not only critical to mitigating the heightened tensions in the Korean Peninsula but also critical steps towards the reunification of the Koreas and a gradual transition from one the last bastion of communism to a true “Democratic Republic of Korea”. North Korea has argued against complete denuclearization citing national security. There is need for a fundamental shift in nuclear diplomacy by transferring all nuclear arsenals in national stockpiles and the exclusive authority to nuclear acquisition from member states to the United Nations as an association of sovereign states. To this end, the IAEA statute, the NPT 2019 review treaty template should be incorporated into the United Nations Charter as Additional Protocols. A new organ should be created to oversee the global nuclear order under the UN in the title of the United Nations Atomic Energy Council (UNAEC). The current five permanent members of the UNSC will still play complimentary role in this emergent nuclear order but multilaterally under the aegisof “the UN”. The 2020 review conference should be utilized to kick start the final negotiations to transfer the international nuclear regime/jurisdictions under the NPT to the United Nations.The conference should also serve to garner support among the diplomatic community for the finalization of the ratification of the Fiftieth instrument of the inchoate Treaty on the Prohibition of Nuclear Weapons which should be incorporated into the UN Charter as additional Protocols. This landmark reform when actualized will give the United Nations the unparalleled diplomatic clout on matters that borders on international peace and security, unveiling the United Nations Peace in the rubric: “Pax- United Nations”. On North Korea, the paper stands with stronger sanctions regime, embargoes, assets freezes and diplomatic alterations to compel the defiant regime to yield to the call for total denuclearization as the Democratic Peoples‟ Republic of North Korea hasdemonstrated some of the worst diplomatic characters typical of Machiavellian diplomacy fraught with secrecy and double-dealings