Peace and security

The 1945 UN Charter envisaged a system of regulation that would ensure "the least diversion for armaments of the world's human and economic resources". The advent of nuclear weapons came only weeks after the signing of the Charter and provided immediate impetus to concepts of arms limitation and disarmament. In fact, the first resolution of the first meeting of the General Assembly (24 January 1946) was entitled "The Establishment of a Commission to Deal with the Problems Raised by the Discovery of Atomic Energy" and called upon the commission to make specific proposals for "the elimination from national armaments of atomic weapons and of all other major weapons adaptable to mass destruction".
Disarmament

The UN has established several forums to address multilateral disarmament issues. The principal ones are the First Committee of the General Assembly, the UN Disarmament Commission, and the Conference on Disarmament. Items on the agenda include consideration of the possible merits of a nuclear test ban, outer-space arms control, efforts to ban chemical weapons and land mines, nuclear and conventional disarmament, nuclear-weapon-free zones, reduction of military budgets, and measures to strengthen international security.

Peacekeeping


UN peacekeepers are sent to regions where armed conflict has recently ceased (or paused) to enforce the terms of peace agreements and to discourage combatants from resuming hostilities. Since the UN does not maintain its own military, peacekeeping forces are voluntarily provided by member states of the UN. All UN peacekeeping operations must be approved by the Security Council.


The founders of the UN had envisaged that the UN would act to prevent conflicts between nations and make future wars impossible. Those hopes have not been fully realized. During the Cold War (from about 1945 until 1991), the division of the world into hostile camps made peacekeeping agreement extremely difficult. Following the end of the Cold War, there were renewed calls for the UN to become the agency for achieving world peace, as there are several dozen ongoing conflicts that continue to rage around the globe. However, the breakup of the Soviet Union also left the U.S. in a unique position of global dominance, creating a variety of new challenges for the UN.

UN peacekeeping light armed mechanised vehicle in Bovington tank museum, Dorset
The UN Peace-Keeping Forces (called the Blue Helmets) received the 1988 Nobel Prize for Peace. In 2001, the UN and Secretary General Kofi Annan won the Nobel Peace Prize "for their work for a better organized and more peaceful world." The UN maintains a series of United Nations Medals awarded to military service members who enforce UN accords. The first such decoration issued was the United Nations Service Medal, awarded to UN forces who participated in the Korean War. The NATO Medal is designed on a similar concept and both are considered international decorations instead of military decorations.

Assessments
A large share of UN expenditures addresses the core UN mission of peace and security. The peacekeeping budget for the 2005-2006 fiscal year is approximately $5 billion (compared to approximately $1.5 billion for the UN core budget over the same period), with some 70,000 troops deployed in 17 missions around the world.
UN peace operations are funded by assessments, using a formula derived from the regular funding scale, but including a weighted surcharge for the five permanent Security Council members, who must approve all peacekeeping operations. This surcharge serves to offset discounted peacekeeping assessment rates for less developed countries. In December 2000, the UN revised the assessment rate scale for the regular budget and for peacekeeping. The peacekeeping scale is designed to be revised every six months.

Successes in security issues
The Human Security Report 2005, produced by the Human Security Centre at the University of British Columbia with support from several governments and foundations, documented a dramatic, but largely unrecognized, decline in the number of wars, genocides and human rights abuses since the end of the Cold War. Statistics include:
a 40% drop in violent conflict;
an 80% drop in the most deadly conflicts; and
an 80% drop in genocide and politicide.
The report argued that international activism — mostly spearheaded by the UN — has been the main cause of the post–Cold War decline in armed conflict, though the report indicated the evidence for this contention is mostly circumstantial.
In the area of Peacekeeping, successes include:
The US Government Accountability Office concluded that UN Peacekeeping is eight times less expensive than funding a U.S. force.
A 2005 RAND Corp study found the UN to be successful in two out of three peacekeeping efforts. It also compared UN nation-building efforts to those of the U.S., and found that of eight UN cases, seven are at peace, whereas of eight U.S. cases, four are at peace.

Failures in security issues
In many cases UN members have shown reluctance to achieve or enforce Security Council resolutions. Such failures stem from the UN's intergovernmental nature — in many respects it is an association of 192 member states who must reach consensus, not an independent organization.
Other serious security failures include:
Failure to prevent the 1994 Rwandan genocide, which resulted in the killings of nearly a million people, due to the refusal of security council members to approve any military action.
Failure by MONUC (UNSC Resolution 1291) to effectively intervene during the Second Congo War, which claimed nearly five million people in the Democratic Republic of Congo (DRC), 1998-2002, and in carrying out and distributing humanitarian aid.Failure to intervene in the 1995 Srebrenica massacre: despite the fact that the UN designated Srebrenica a "safe haven" for refugees and assigned 600 Dutch peacekeepers to protect it, the peacekeeping force was not authorised to use force.
Failure to successfully deliver food to starving people in Somalia; the food was instead usually seized by local warlords. A U.S./UN attempt to apprehend the warlords seizing these shipments resulted in the 1993 Battle of Mogadishu.
Failure to implement provisions of United Nations Security Council Resolutions related to the Israeli-Palestinian conflict. Failed to prevent or help sufficiently in the area of Darfur genocide: a crisis still exists in that area.
Failed to prevent the Iraq War in 2003

Peace enforcement

The U.N. has not only acted to keep the peace but also intervened in armed conflicts, the first of which was the Korean War (1950-1953), or more recently the intervention in Kosovo in 1999.