UNESCO is most importantly an idea.

Americans tend to rank organizations size, bigger being better. Big budgets and big staffs are thought to lead to big impacts. The U.S. not only spends more on its military than any other country, it spends much more than the next ten biggest spenders combined. General motors makes millions of cars a year, and Microsoft and Apple seem to mint money as profits. They typify America's thoughts of big impacts,

UNESCO is, in terms of its charter, tiny. The decentralized agency of the United Nations system responsible for education, science, culture and communication has a budget less than that of my local school district and has come down in size over the last couple of years from under 2,000 people. Yet

• it is to promote education at all levels globally; 
• it is the lead agency in the UN system for earth and water sciences, as well the study of biodiversity, and the basic sciences; 
• it has programs in social science and ethics, not to mention sports.
• it promotes museums, seeks to reduce the international trade in stolen cultural artifacts, and to encourage the protection of tangible and intangible cultural heritage;
• it manages its flagship program certifying cites as worthy of World Heritage status;
• it encourages theater, literature, and music; 
• it seeks to promote freedom of expression and protect journalists; and
• it seeks to promote the dissemination and utilization of communications media, including the Internet.

The United States is part of the reason that the resources are so small compared with the breadth of UNESCO's mission. When the Organization was conceived by the allied ministers of education during World War II, they hoped for an organization that might finance the rebuilding of the educational infrastructure of Europe after the war. The United States, which alone was left with its industrial might untouched by the war, preferred to control aid to Europe directly using the Marshall Plan and through the Bank for Reconstruction and Development (which became the core of the World Bank family of organizations, and the model for other multinational development banks). Then, the United States (and the United Kingdom) withdrew from UNESCO in 1984 taking its contributions with it, and did not rejoin the Organization until 2003. Then, in 2011 the USA (then responsible for 22 percent of the UNESCO regular budget) stopped funding UNESCO entirely; it has at this date neither resigned from the organization nor resumed funding for it.

The Constitution of UNESCO states in its preamble, "(t)hat since wars begin in the minds of men, it is in the minds of men that the defences of peace must be constructed." It goes on to state:

That a peace based exclusively upon the political and economic arrangements of governments would not be a peace which could secure the unanimous, lasting and sincere support of the peoples of the world, and that the peace must therefore be founded, if it is not to fail, upon the intellectual and moral solidarity of mankind.  

For these reasons, the States Parties to this Constitution, believing in full and equal opportunities for education for all, in the unrestricted pursuit of objective truth, and in the free exchange of ideas and knowledge, are agreed and determined to develop and to increase the means of communication between their peoples and to employ these means for the purposes of mutual understanding and a truer and more perfect knowledge of each other’s lives;  

In consequence whereof they do hereby create the United Nations Educational, Scientific and Cultural Organization for the purpose of advancing, through the educational and scientific and cultural relations of the peoples of the world, the objectives of international peace and of the common welfare of mankind for which the United Nations Organization was established and which its Charter proclaims. 

The importance of UNESCO lies not so much in the actions of a couple of thousand people working in its offices as in the large number of people and organizations that have joined around it in support of that mission.

Perhaps its role in the Education for All movement can illustrate the point. UNESCO sponsored meetings some 25 and 15 years ago in which the participants put forward the idea of a global effort to assure education for all. With encouragement of UNESCO, an educational objective was included by the United Nations in the Millennium Development Goals. However, it was governments and non-governmental organizations that would carry out the work of building schools, training teachers, developing curricula, providing teaching materials, and financing a huge expansion of educational services in developing countries. Teachers by the millions carried out the real work of teaching hundreds of millions of kids.

UNESCO helped countries to establish educational statistics systems that would allow progress to be measured and compared with benchmarks and other countries. It convened meetings of educators and ministers of education to discuss progress, and it published the Education for All Global Monitoring Reports. In short, UNESCO used its convening power to mobilize a global mass movement, which will eventually have an impact on the minds of men globally.

UNESCO helped catalyze the creation of the European Center for Nuclear Research (better known as CERN) decades ago. It had become apparent that experiments in particle physics were going to be expense, and would become still more expensive as time progressed and higher and higher energies were required. European scientists were aware that their countries could not participate in that research unless they jointly financed the facilities. Indeed today, CERN experiments have become so expensive that the United States and Japan join in their finance with European  nations. CERN has made important contributions to science, most recently providing the evidence confirming the existence of the Higgs boson, and thus completing the model of basic particles. Perhaps more familiar, Tim Berners-Lee created the software underlying the World Wide Web; he and CERN put that in public domain, hugely increasing the sharing of information worldwide on the Internet.

So too, there are many declarations and conventions developed under the convening power of UNESCO. They express a consensus among nations about key international issues. Each convention imposes treaty obligations on its ratifying nations, and many UNESCO conventions have so long a history and so many signatories that they now constitute international law.

Governments, associations (many of them representing millions of people), non-governmental organizations and even business enterprises have affiliated with UNESCO and/or partnered with it in support of the Organization's mission. So too UNESCO has established huge networks of world heritage sites, bioreserves, geoparks, and wetlands that implement parts of UNESCO's program (on their own dime). Not only are large numbers of people involved in managing these sites, but many millions visit them each year.

There are a number of UNESCO centers, partially or fully supported by donors, but accepted by UNESCO as relevant to its mission. So too there is a large network of affiliated schools and a network of university UNESCO Chairs and specialized university networks; these are supported by others but inscribed by UNESCO as implementing portion's of UNESCO's mission after scrutiny of their charters.

UNESCO is unique among UN agencies in that it has National Commissions in its member states. The National Commissions not only include thousand of members worldwide, but also link the Organization with the communities of educators, scientists, cultural leaders, and leaders in communication in their countries. There are also thousands of clubs that have been created worldwide to support UNESCO and its mission.

Thus UNESCO has a huge influence worldwide, not by the direct services provided by its staff from their offices, but by the much, much larger community of people who believe in its mission and act to build the defenses of peace in the minds of men everywhere.

States have been at war, one with another for thousands of years. Our earliest records from Egypt, Greece, the bible, China and India tell of war and conflict. How long will it take to build the defenses of peace in the minds of men? I suppose centuries, but UNESCO has made a start.