"To save succeeding generations from the scourge of war" are among the first very words of the UN Charter (in its Preamble), and those words were the main motivation for creating the United Nations, whose founders had lived through the devastation of two world wars by 1945. Since the UN's creation on 24 October 1945 (the date its Charter came into force), the United Nations has often been called upon to prevent disputes from escalating into war, or to help restore peace following the outbreak of armed conflict, and to promote lasting peace in societies emerging from wars.

Security Council

Over the decades, the UN has helped to end numerous conflicts, often through actions of the Security Council — the organ with primary responsibility, under the United Nations Charter, for the maintenance of international peace and security. When it receives a complaint about a threat to peace, the Council first recommends that the parties seek an agreement by peaceful means. In some cases, the Council itself investigates and mediates. It may appoint special representatives or request the Secretary-General to do so, or to use his good offices. It may set forth principles for a peaceful settlement.

When a dispute leads to fighting, the Council's first concern is to end it as soon as possible. On many occasions, the Council has issued ceasefire directives, which have helped to prevent major hostilities. It also deploys UN peacekeeping operations to reduce tensions in troubled areas, keep opposing forces apart, and create conditions for sustainable peace after settlements have been reached. The Council may decide on enforcement measureseconomic sanctions (such as trade embargoes) or collective military action.

General Assembly

According to the Charter, the General Assembly can make recommendations on the general principles of cooperation for maintaining international peace and security, including disarmament, and for the peaceful settlement of any situation that might impair friendly relations among nations. The General Assembly may also discuss any question relating to international peace and security and make recommendations the Security Council is not currently discussing the issue. 

Pursuant to its “Uniting for Peace” resolution of November 1950 (resolution 377 (V)), the General Assembly may also take action if the Security Council fails to act, owing to the negative vote of a Permanent Member, in a case where there appears to be a threat to, or breach of peace, or an act of aggression. The Assembly can consider the matter immediately in order to make recommendations to Members for collective measures to maintain, or restore, international peace and security.


The Charter empowers the Secretary-General to "bring to the attention of the Security Council any matter which in his opinion may threaten the maintenance of international peace and security." One of the most vital roles played by the Secretary-General is the use of his "good offices" – steps taken publicly and in private that draw upon his independence, impartiality and integrity to prevent international disputes from arising, escalating or spreading.

Conflict Prevention

The main strategies to prevent disputes from escalating into conflict, and to prevent the recurrence of conflict, are preventive diplomacy and preventive disarmament. Preventive diplomacy refers to action taken to prevent disputes from arising or escalating into conflicts, and to limit the spread of conflicts as they arise. It may take the form of mediation, conciliation or negotiation.

Preventive diplomacy

Early warning is an essential component of prevention, and the United Nations carefully monitors developments around the world to detect threats to international peace and security, thereby enabling the Security Council and the Secretary-General to carry out preventive action. Envoys and special representatives of the Secretary-General are engaged in mediation and preventive diplomacy throughout the world. In some trouble spots, the mere presence of a skilled envoy can prevent the escalation of tension. These envoys often cooperate with regional organizations.

Preventive disarmament

Complementing preventive diplomacy is preventive disarmament, which seeks to reduce the number of small arms in conflict-prone regions. In El Salvador, Liberia, Sierra Leone, Timor-Leste and elsewhere, this has entailed demobilizing combat forces, as well as collecting and destroying their weapons as part of an overall peace agreement. Destroying yesterday’s weapons prevents their use in tomorrow’s wars.

Preventing Genocide and Responsibility to Protect

Prevention requires apportioning responsibility and promoting collaboration between the concerned States and the international community. The duty to prevent and halt genocide and mass atrocities lies first and foremost with the State, but the international community has a role that cannot be blocked by the invocation of sovereignty. Sovereignty no longer exclusively protects States from foreign interference; it is a charge of responsibility where States are accountable for the welfare of their people. This principle is enshrined in article 1 of the Genocide Convention and embodied in the principle of “sovereignty as responsibility” and in the concept of the Responsibility to Protect.

The Special Adviser on the Prevention of Genocide acts as a catalyst to raise awareness of the causes and dynamics of genocide, to alert relevant actors where there is a risk of genocide, and to advocate and mobilize for appropriate action. The Special Adviser on the Responsibility to Protect leads the conceptual, political, institutional and operational development of the Responsibility to Protect. The efforts of their Office include alerting relevant actors to the risk of genocide, war crimes, ethnic cleansing and crimes against humanity, enhancing the capacity of the United Nations to prevent these crimes, including their incitement.


United Nations peacekeeping operations are a vital instrument employed by the international community to advance peace and security.

The first UN peacekeeping mission was established in 1948 when the Security Council authorized the deployment of the United Nations Truce Supervision Organization (UNTSO) to the Middle East to monitor the Armistice Agreement between Israel and its Arab neighbours. Since then, there have been more than 70 UN peacekeeping operations around the world.

Over 72 years, UN peacekeeping has evolved to meet the demands of different conflicts and a changing political landscape. Born at the time when Cold War rivalries frequently paralyzed the Security Council, UN peacekeeping goals were primarily limited to maintaining ceasefires and stabilizing situations on the ground, so that efforts could be made at the political level to resolve the conflict by peaceful means. 

UN peacekeeping expanded in the 1990s, as the end of the Cold War created new opportunities to end civil wars through negotiated peace settlements. Many conflicts ended, either through direct UN mediation, or through the efforts of others acting with UN support. Countries assisted included El Salvador, Guatemala, Namibia, Cambodia, Mozambique, Tajikistan, and Burundi. In the late nineties, continuing crises led to new operations in the Democratic Republic of the Congo, the Central African Republic, Timor Leste, Sierra Leone and Kosovo.

In the new millennium, peacekeepers have been deployed to LiberiaCôte d'IvoireSudanSouth SudanHaiti, and Mali.

Today's conflicts are less numerous but deeply rooted. For example, the Democratic Republic of the Congo, Darfur, and South Sudan today, are in a second or third wave of conflict. And many are complicated by regional dimensions that are key to their solution. In fact, some two-thirds of peacekeeping personnel today are deployed amid ongoing conflict, where peace agreements are shaky or absent. Conflicts today are also increasingly intensive, involving determined armed groups with access to sophisticated armaments and techniques.

The nature of conflict has also changed over the years. UN peacekeeping, originally developed as a means of resolving inter-State conflict, has been increasingly applied over time to intra-State conflicts and civil wars. Although the military remains the backbone of most peacekeeping operations, today’s peacekeepers perform a variety of complex tasks, from helping to build sustainable institutions of governance, through human rights monitoring and security sector reform, to the disarmament, demobilization and reintegration of former combatants, and demining.


Within the United Nations, peacebuilding refers to efforts to assist countries and regions in their transitions from war to peace and to reduce a country's risk of lapsing or relapsing into conflict by strengthening national capacities for conflict management, and laying the foundations for sustainable peace and development.

Building lasting peace in war-torn societies is a daunting challenge for global peace and security. Peacebuilding requires sustained international support for national efforts across the broadest range of activities. For instance, peacebuilders monitor ceasefires, demobilize and reintegrate combatants, assist the return of refugees and displaced persons, help to organize and monitor elections of a new government, support justice and security sector reforms, enhance human rights protections, and foster reconciliation after past atrocities.

Peacebuilding involves action by a wide array of organizations of the UN system, including the World Bank, regional economic commissions, NGOs and local citizens’ groups. Peacebuilding has played a prominent role in UN operations in Bosnia and Herzegovina, Cambodia, El Salvador, Guatemala, Kosovo, Liberia and Mozambique, as well as more recently in Afghanistan, Burundi, Iraq, Sierra Leone and Timor-Leste. An example of inter-state peacebuilding has been the UN Mission in Ethiopia and Eritrea.

Recognizing that the UN needs to better anticipate and respond to the challenges of peacebuilding, the 2005 World Summit approved the creation of a new Peacebuilding Commission. In the resolutions establishing the Peacebuilding Commissionresolution 60/180 and resolution 1645, the UN General Assembly and the Security Council mandated it to bring together all relevant actors to advise on the proposed integrated strategies for post-conflict peacebuilding and recovery; to marshal resources and help ensure predictable financing for these activities; and to develop best practices in collaboration with political, security, humanitarian and development actors.

The resolutions also identify the need for the Commission to extend the period of international attention on post-conflict countries, and where necessary, highlight any gaps which threaten to undermine peacebuilding.

The General Assembly and Security Council resolutions establishing the Peacebuilding Commission also provided for the establishment of a Peacebuilding Fund and a Peacebuilding Support Office.

The Rule of Law

Promoting the rule of law at the national and international levels is at the heart of the United Nations’ mission.  Establishing respect for the rule of law is fundamental to achieving a durable peace in the aftermath of conflict, to the effective protection of human rights, and to sustained economic progress and development.  The principle that everyone – from the individual to the State itself – is accountable to laws that are publicly promulgated, equally enforced and independently adjudicated, is a fundamental concept which drives much of the United Nations work.  The main United Nations organs, including the General Assembly and the Security Council, play essential roles in supporting Member States to strengthen the rule of law, as do many United Nations entities.

Responsibility for the overall coordination of rule of law work by the United Nations system rests with the Rule of Law Coordination and Resource Group, chaired by the Deputy Secretary-General and supported by the Rule of Law Unit.  Members of the Group are the principals of 20 United Nations entities engaged in supporting Member States to strengthen the rule of law.  Providing support from headquarters to rule of law activities at the national level, the Secretary-General designated the Department of Peacekeeping Operations (DPKO) and the United Nations Development Programme (UNDP) as the joint global focal point for the police, justice and corrections areas in the rule of law in post-conflict and other crisis situations. 

Women and Children in Conflict

In contemporary conflicts, up to 90 per cent of casualties are civilians, mostly women and children. Women in war-torn societies can face specific and devastating forms of sexual violence, which are sometimes deployed systematically to achieve military or political objectives. Moreover, women continue to be poorly represented in formal peace processes, although they contribute in many informal ways to conflict resolution.

However, the UN Security Council in its resolution 1325 on women, peace and security has recognized that including women and gender perspectives in decision-making can strengthen prospects for sustainable peace. The landmark resolution addresses the situation of women in armed conflict and calls for their participation at all levels of decision-making on conflict resolution and peacebuilding.

Since the agenda was set with the core principles of resolution 1325, the Security Council adopted three supporting resolutions — 18201888 and 1889. All four resolutions focus on two key goals: strengthening women’s participation in decision-making and ending sexual violence and impunity.

Since 1999, the systematic engagement of the UN Security Council has firmly placed the situation of children affected by armed conflict as an issue affecting peace and security. The Security Council has created a strong framework and provided the Secretary-General with tools to respond to violations against children. The Special Representative of the Secretary-General for Children and Armed Conflict serves as the leading UN advocate for the protection and well-being of children affected by armed conflict.

Peaceful uses of outer space

The UN works to ensure that outer space is used for peaceful purposes and that the benefits from space activities are shared by all nations. This concern for the peaceful uses of outer space began soon after the launch of Sputnik — the first artificial satellite — by the Soviet Union in 1957 and has kept pace with advances in space technology. The UN has played an important role by developing international space law and by promoting international cooperation in space science and technology.

The Vienna-based United Nations Office for Outer Space serves as the secretariat for the Committee on the Peaceful Uses of Outer Space and its subcommittees, and assists developing countries in using space technology for development.