An intergovernmental organization (in most Commonwealth countries, usually intergovernmental organisation), sometimes rendered as an international governmental organization and both abbreviated as IGO, is an organization composed primarily of sovereign states (referred to as member states), or of other intergovernmental organizations. Intergovernmental organizations are often called international organizations, although that term may also include international nongovernmental organization such as international nonprofit organizations or multinational corporations.
Intergovernmental organizations are an important aspect of public international law. IGOs are established by treaty that acts as a charter creating the group. Treaties are formed when lawful representatives (governments) of several states go through a ratification process, providing the IGO with an international legal personality.
Intergovernmental organizations in a legal sense should be distinguished from simple groupings or coalitions of states, such as the G8 or the Quartet. Such groups or associations have not been founded by a constituent document and exist only as task groups.
Intergovernmental organizations must also be distinguished from treaties. Many treaties (such as the North American Free Trade Agreement, or the General Agreement on Tariffs and Trade before the establishment of the World Trade Organization) do not establish an organization and instead rely purely on the parties for their administration becoming legally recognized as an ad hoc commission. Other treaties have established an administrative apparatus which was not deemed to have been granted international legal personality.
Types and purposes 
Intergovernmental organizations differ in function, membership and membership criteria. They have various goals and scopes, often outlined in the treaty or charter. Some IGOs developed to fulfill a need for a neutral forum for debate or negotiation to resolve disputes. Others developed to carry out mutual interests with unified aims to preserve peace through conflict resolution and better international relations, promote international cooperation on matters such as environmental protection, to promote human rights, to promote social development (education, health care), to render humanitarian aid, and to economic development. Some are more general in scope (the United Nations) while others may have subject-specific missions (such as Interpol or the International Organization for Standardization and other standards organizations). Common types include:
- Worldwide or global organizations - generally open to nations worldwide as long as certain criteria are met. This category includes the United Nations (UN) and its specialized agencies, the Universal Postal Union, Interpol, the World Trade Organization (WTO), the World Customs Organization (WCO), World Nature Organization (WNO), and the International Monetary Fund (IMF).
- Regional organizations - open to members from a particular region or continent of the world. This category includes the Council of Europe (CoE), European Union (EU), NATO, Organization for Security and Co-operation in Europe, African Union (AU), Organization of American States (OAS), Association of Southeast Asian Nations (ASEAN), Arab League, and Union of South American Nations.
- Cultural, linguistic, ethnic, religious, or historical organizations - open to members based on some cultural, linguistic, ethnic, religious, or historical link. Examples include the Commonwealth of Nations, Organisation internationale de la Francophonie, Community of Portuguese Language Countries, Latin Union, Turkic Council, International Organization of Turkic Culture, or Organisation of Islamic Cooperation
- Economic organizations - based on economic organization. Some are dedicated to free trade, the reduction of trade barriers (the World Trade Organization) and International Monetary Fund. Others are focused on international development. International cartels, such as OPEC, also exist. The Organisation for Economic Co-operation and Development was founded as an economics-focused organization. An example of a recently formed economic IGO is the Bank of the South.
- Educational organizations - centered around tertiary level study. Academy of European Law offers training in European law to lawyers, judges, barristers, solicitors, in-house counsel and academics. EUCLID (university) chartered as a university and umbrella organization dedicated to sustainable development in signatory countries and United Nations University efforts to resolve the pressing global problems that are the concern of the United Nations, its Peoples and Member States.
The Union of International Associations publishes an annual directory of organizations and provides ancillary information on most international organizations, both intergovernmental and non-governmental.
The United Nations Mission:
- To maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace;
- To develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, and to take other appropriate measures to strengthen universal peace;
- To achieve international co-operation in solving international problems of an economic, social, cultural, or humanitarian character, and in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion; and
- To be a centre for harmonizing the actions of nations in the attainment of these common ends.
Membership: 193 Member States. Membership is "...open to all other peace-loving states which accept the obligations contained in the present Charter and, in the judgment of the Organization, are able and willing to carry out these obligations."
World Bank Mission Statement:
- "To fight poverty with passion and professionalism for lasting results. To help people help themselves and their environment by providing resources, sharing knowledge, building capacity and forging partnerships in the public and private sectors."
Membership: 186 Members made up of government-owned organizations.
North Atlantic Treaty Organization (NATO) Mission:
- "The Parties to this Treaty reaffirm their faith in the purposes and principles of the Charter of the United Nations and their desire to live in peace with all peoples and all governments.
They are determined to safeguard the freedom, common heritage and civilization of their peoples, founded on the principles of democracy, individual liberty and the rule of law. They seek to promote stability and well-being in the North Atlantic area. They are resolved to unite their efforts for collective defence and for the preservation of peace and security. They therefore agree to this North Atlantic Treaty."
Membership: "NATO is an Alliance that consists of 28 independent member countries."
While treaties, alliances, and multilateral conferences had existed for centuries, IGOs only began to be established in the 19th century. Among the first were the Central Commission for Navigation on the Rhine, initiated in the aftermath of the Napoleonic Wars, and the future International Telegraph Union, which was founded by the signing of the International Telegraph Convention by 20 countries in May 1865. Of notable significance was the emergence of the League of Nations following World War One, designed as an institution to foster collective security in order to sustain peace.
Expansion and growth 
Held and McGrew (2002) counted more than 6,743  IGOs worldwide, and this number continues to rise. This increase may be attributed to globalization, which increases and encourages the cooperation among and within states. Globalization has also provided easier means for IGO growth, as a result of increased international relations. This is seen economically, politically, militarily, as well as on the domestic level. Economically, IGOs gain material and non-material resources for economic prosperity. IGOs also provide more political stability within the state and among differing states. Military alliances are also formed by establishing common standards in order to ensure security of the members to ward off outside threats. Lastly, the formation has encouraged autocratic states to develop into democracies in order to form an effective and internal government.
Participation and involvement 
There are several different reasons a state may choose membership in an intergovernmental organization. But there are also reasons membership may be rejected. These reasons are explored in the sections below.
Reasons for participation:
- Economic rewards: In the case of the North American Free Trade Agreement (NAFTA), many different countries receive economic benefits from membership in the free trade agreement. For example, Mexican companies are given better access to U.S. markets due to their membership.
- Political influence: Smaller countries, such as Portugal and the Netherlands, who do not carry much political clout on the international stage, are given a substantial increase in influence through membership in IGOs, such as the European Union. Also for countries with more influence such as France and Germany they are beneficial as the nation increases influence in the smaller countries' internal affairs and expanding other nations dependence on themselves, so to preserve allegiance
- Security: Membership in an IGO such as NATO gives security benefits to member countries. This provides an arena where political differences can be resolved.
- Improve democracy and the likelihood of democratic survival: It has been noted that member countries experience a greater degree of democracy and those democracies survive longer.
Reasons for rejecting membership:
- Loss of sovereignty: Membership often comes with a loss of state sovereignty as treaties are signed which require cooperation on the part of all member states.
- Insufficient benefits: Often membership does not bring about substantial enough benefits to warrant membership in the organization.
Strengths and weaknesses 
These are some of the strengths and weaknesses of IGOs:
- They hold state authority.
- Their institutions are permanent.
- They provide a forum for discussion.
- They are issue specific.
- They provide information.
- They allow multilateral cooperation.
- Membership is limited. Prohibits the membership of private citizens. This makes IGOs undemocratic. In addition, not all IGOs allow universal membership.
- IGOs often overlap resulting in a complex network.
- States have to give up part of their sovereignty, which weakens the state's ability to assert its authority.
- Inequality among state members creates biases and can lead powerful states to misuse these organizations.
They can be deemed unfair as countries with a higher percentage voting power have the right to veto any decision that is not in their favor, leaving the smaller countries powerless.
See also 
- List of intergovernmental organizations
- List of organizations with .int domain names
- List of supranational environmental agencies
- International organisations in Europe
- International trade/Index of international trade topics
- International financial institutions
- Non-aggression pact
- Supranational aspects of international organizations
- Supranational union
- Trade bloc
- World government
Further readings and external references 
- Claude, I.L. (1959). Swords into Plowshares: The problems and progress of international organization. New York: Random House
- http://untreaty.un.org/English/Seminar/Laos_03/intorganizations.ppt[dead link]
- http://www.aallnet.org/sis/fcilsis/Syllabi/kuehl/Introduction%20to%20Intergovernmental%20Organizations%20and%20Non-Governmental.ppt[dead link]
- IGO search Free service allowing search through websites of all intergovernmental organizations (IGOs) as recognized and profiled by the Union of International Associations.
- ASIL-RIO reports Reports on the activities of various intergovernmental organizations maintained by the American Society of International Law.
- Walker, Gloria. "Consolidation and Corruption: The Effect of IGO Membership on Level of Corruption in Emerging Democracies" Paper presented at the annual meeting of the American Political Science Association, Hilton Chicago and the Palmer House Hilton, Chicago, IL, Sep 02, 2004 <Not Available>. 2009-05-26 <http://www.allacademic.com/meta/p61398_index.html>
- IGO Search: IGO/NGO google custom search engine built by the Govt Documents Round Table (GODORT) of the American Library Association.
- "Charter of the United Nations: Chapter I: Purposes and Principles". Un.org. Retrieved 2011-09-19.
- "Charter of the United Nations: Chapter II: Membership". Un.org. 1942-01-01. Retrieved 2011-09-19.
- "About Us - Challenge". Web.worldbank.org. 2010-09-20. Retrieved 2011-09-19.
- "NATO - Official text: The North Atlantic Treaty, 04-Apr.-1949". Nato.int. 2008-12-09. Retrieved 2011-09-19.
- "NATO - Member countries". Nato.int. 2009-03-10. Retrieved 2011-09-19.
- Held and McGrew, 2002: 18-19
- Shannon, Megan. "The Expansion of International Organizations" Paper presented at the annual meeting of the American Political Science Association, Hilton Chicago and the Palmer House Hilton, Chicago, IL, Sep 02, 2004 <Not Available>. 2009-05-26