United Nations (UN), international organization established immediately after World War II. It replaced the League of Nations.

The Charter of the United Nations comprises a preamble and 19 chapters divided into 111 articles. The charter sets forth the purposes of the UN as: the maintenance of international peace and security; the development of friendly relations among states; and the achievement of cooperation in solving international economic, social, cultural, and humanitarian problems. It expresses a strong hope for the equality of all people and the expansion of basic freedoms.

The earliest concrete plan for the formation of a new world organization was begun under the aegis of the U.S. State Department late in 1939. The name United Nations was coined by President Franklin Delano Roosevelt in 1941 to describe the countries fighting against the Axis. It was first used officially on Jan. 1, 1942, when 26 states joined in the Declaration by the United Nations, pledging themselves to continue their joint war effort and not to make peace separately. The need for an international organization to replace the League of Nations was first stated officially on Oct. 30, 1943, in the Moscow Declaration, issued by China, Great Britain, the United States, and the USSR.

Since its foundation in 1945, the United Nations was conceived as an instrument to face the most relevant global challenges emerging in the international system. Its structure and functioning was designed to curtail the negative effects of globalization, such as the spread of transnational threats, and to grant peace and security. Although for many time the UN system had proved to be successful in addressing a number of global issues, during the last years, it has revealed some important deficiencies and weaknesses. This has made the Member States call for a reform of the UN in terms of structure and powers.

The maintenance of peace and security has always been a priority to the UN Member States. To achieve this objective, the organization was provided with an executive organism, which would have held the exclusive power to deal with those issues: the Security Council. Its action to promote peace and security helped the international community to solve the worst crisis of the past century and to avert the horrors of another World War. This was the case during the ‘60s and ‘70s when the political commitment of the Security Council helped to prevent the escalation of the US-USSR conflict.

Those were also the years which saw a relevant enlargement of the membership in the UN, as the new born states, resulting from the decolonization process, submitted their admission request to join the international security system created in 1945. This showed that, although their interests and objectives might have been different in terms of economic goals or social policies, they shared with the UN’s founders a primary concern: the maintenance of peace and security. Indeed, this was an essential condition for the new born states, as international stability would have allowed them to concentrate on internal processes of state-building and nation-building.

Not only did the UN develop as a successful universal International Organization but it also became a forum to discuss and address other important issues such as equitable and sustainable development, economic and monetary stability, etc. The General Assembly was conceived to meet this goal and, during its activity, it has proved to be essential to elaborate a joint action to face global issues.

Despite the fact that the UN’s commitment to deal with international questions has been outstanding, nowadays its system reveals some important weaknesses.

Firstly, the new contemporary global challenges are jeopardizing its solidity and effectiveness. An example comes from the spread of security threats, such as transnational terrorism and illicit arms trade. These phenomena have highlighted the limits of the Security Council’s action, and, in general, of the UN’s security system to assure peace and international stability.

When threats come from non-state actors (which are not linked to any specific territory and do not represent any political entity), it is tough for the UN to elaborate an effective plan to hinder them. To many observers, the main deficiency of the UN’s security system consists in the lack of an international army.

Initially, the founders planned to build a military structure under the direct control of the Security Council in order to successfully implement the common military actions to restore peace (art. 43 and 45 UN Chart).

However, the project failed due to the reluctance of its Member States to create a common army. Not only the UN military structure would have had an outstanding destructive capacity compared to the national armies but it would have also required a relevant financial commitment of its Member States.

A second weakness concerning the UN’s functioning is related to the lack of democratic mechanisms and accountability, which affects its structure. The composition of the Security Council still reflects the power distribution of 1945 as the five permanent members (United States, France, United Kingdom, China and Russia) hold more powers and prerogatives (e.g. the veto power) than the non-permanent ones. Since the power distribution has strongly changed during the last decades and values of equality between sovereign states have spread in the international community, the composition of the Security Council appears to be anachronistic.

The third main deficiency of the UN system consists in the absence of a mechanism to empower the judgements of the International Court of Justice. When the ICJ was created, it was agreed that states would have had to accept the Court’s jurisdiction in order to allow it to judge their controversies. This was the consequence of two circumstances. Firstly, there was no world government that could force states to respect and enforce the judgements of the ICJ. Secondly, being states jealous of their independence and powers, they prevented any attempt to limit their sovereignty. In this way, no mechanism to assure the respect of the Court’s decisions was provided and, nowadays, the implementation of its judgements still rests on the will of the Member States.

Highlighting these deficiencies has brought the international community to urge a structural and substantial reform of the UN system. It is undeniable that, since its foundation, UNO has undergone a number of considerable transformations. However, some important progress still has to be attained in order to improve its efficiency and to grant the effectiveness of its action up against the new global challenges, contemporary security issues and international threats.