Has the UN succeeded in its primary objective of maintaining international peace and security in the world? Liberal institutionalists opine that the UN has succeeded in maintaining global peace and security as it has averted major global conflicts since 1945. Despite intense security competition and proxy warfare during the Cold War, the World Organization has played a key role in resolving several global security issues and averting large-scale wars in the world. After the 9/11 incident, a global war on terrorism was launched against non-state actors, but the UN compressed space for direct military confrontation among nation-states. Liberals argue that the World Organization has maintained global peace through various means, including disarmament, nuclear non-proliferation, peacekeeping missions, pacific settlement of disputes, and coercive measures like economic sanctions and collective security measures. Yet, realists offer different rationales for the repulsion of states from a direct collision. To maintain global peace and security, multilateral disarmament and arms limitation have remained the primary objective of the global organization. Although the UN has not eliminated all kinds of weapons which pose serious threats to global peace, it has played a pivotal role in eliminating biological and chemical weapons across the world. In 1972, the UN, after long-sought efforts to globally eliminate biological weapons, passed the Biological Weapons Convention which bans an entire category of weapons of mass destruction. The BWC effectively prohibits the development, production, acquisition, transfer, stockpiling and use of biological and toxin weapons. Moreover, the UN has also passed a convention to eliminate chemical weapons. In 1993, with the conclusion of the Chemical Weapons Convention, the UN finally banned chemical weapons to make the world safe from chemical warfare. With the development of nuclear weapons, global peace and security came under serious threat because of the danger of nuclear war. Although conventional weapons like battle tanks, armoured combat vehicles, large-calibre artillery systems, combat aircraft, warships, attack helicopters, un-crewed combat aerial vehicles, missile and missile launchers, cluster munitions and others may cause humanitarian concern either because of the way they are used or may be used, the development of nuclear weapons has completely changed the global security dynamics. To prevent the spread of nuclear weapons and weapons technology, the UN concluded the Non-Proliferation Treaty which came into force on 5 March 1970. The NPT aims to prevent the spread of nuclear weapons and consists of a three-pillar system-non-proliferation, disarmament and peaceful use of nuclear technology. Other treaties which prohibit nuclear weapon testing to prevent nuclear proliferation are the Partial Test Ban Treaty and the Comprehensive Nuclear Test Ban Treaty. Similarly, peacekeeping missions appear to be another contribution of the UN in establishing global peace and security. The main objective of UN peacekeeping is to help countries navigate the difficult path from conflict to peace across the world. It is a unique global partnership in a combined effort to maintain international peace and security in conflict zones as several countries are unable to transition from conflict to peace without the support of the World Organization. The UN peacekeeping is guided by three basic principles – consent of all parties, impartiality, and non-use of force except in self-defence and defence of the mandate. Currently, there are 11 UN peacekeeping operations deployed in several countries. So far, the UN has completed 61 missions that contributed to the resolution of several conflicts and the subsequent transition to peace. Proxy wars, cyberattacks, grey zone conflicts, false flag operations, use of autonomous weapons and conventional wars under nuclear shadow are the defining features of contemporary wars and conflicts. For resolving conflicts and cultivating peace in the world, the UN also extends several blueprints for the resolution of international disputes. To the parties to any dispute based on consent, the UN charter under articles 33-38 offers numerous methods of pacific settlement of disputes. It involves negotiation, inquiry, mediation, conciliation, arbitration, good offices, judicial settlement, and resort to regional agencies or resolution of disputes under the auspices of the UN. These conflict resolution methods so far have played a constructive role in resolving various disputes across the world. When a state or non-state actor fails to respect international commitments or its behaviour infringes on or threatens the international public order, the UN levies sanctions as a coercive measure to protect international peace and security. Through coercive measures, the UNSC takes actions to maintain or restore global peace and security under Chapter IV of the UN charter by levying economic, military and diplomatic sanctions on regimes, entities, and other actors to regulate their behaviour in the international system. Under Article 41 of the UN charter, the UNSC explores a broad range of enforcement options that do not involve the use of armed forces. Currently, there are 15 sanctions regimes of the UN. These sanctions regimes primarily emphasize facilitating political settlement of conflicts, nuclear nonproliferation and counterterrorism. Even in extreme cases like humanitarian crises or armed aggression, the UNSC may take urgent security measures through combined international enforcement action or collective security to protect international public order, peace and security under Chapter VII of the UN charter. However, political realism offers different rationales. As to realists, even though there has been no major global conflict since the creation of the UN, conflict is not absent altogether in international politics. In the contemporary world, only the dynamics and patterns of conflict have changed. Proxy wars, cyberattacks, grey zone conflicts, false flag operations, use of autonomous weapons and conventional wars under nuclear shadow are the defining features of contemporary wars and conflicts. Besides this, the balance of power, nuclear deterrence, the concept of mutually assured destruction and hegemonic stability with the rise of the US as a global superpower has reduced the risk of escalation among great powers. It is, therefore, not the UN that has prevented major conflicts and ensured global peace so far, but it is the nuclear deterrence along with hegemonic stability that has repelled major countries from confrontation. Today, the Ukraine war, the Palestine conflict and great power competition have brought to the fore the limits of global institutionalism. The UN appears to have failed in preventing those wars and conflicts in which the geopolitical interests of great powers are involved. The writer is a strategic affairs and foreign policy analyst, based in Islamabad.