It is lunchtime at the little Italian diner close to Manhattan's 51st Street. An elderly woman shuffles in wearing slippers and is greeted by everyone behind the counter. Out on the street, two old men, walking their dogs, stop for a chat. Behind them, a beggar rummages in a rubbish bag.
This is the run-down part of First Avenue, only two blocks but a million miles away from one of New York's first curtains of glass - the towering building which houses the United Nations.
Here, limousines line up to collect ambassadors, lesser cars queue for the underground car park and the revolving doors turn at frenetic speed, spewing office workers out into the chill winter air and drawing delegates and petitioners into the air-conditioned lobby.
Built in 1948 on 18 acres of land donated by J. D. Rockefeller at a time when the whole of First Avenue was a rundown slum, the Secretariat Building is one of three belonging to the UN - the other two being the Conference Building and the General Assembly Hall.
It was in 1945 that 51 countries came together to form the UN and since then, the number of member countries has now grown to 185 (Ireland joined in 1955). In the intervening years, the world has seen a significant number of political developments, including the end of the Cold War, the demise of both communism and apartheid, the emergence of many newly independent countries, a critical increase in the number of refugees, continuing conflict in Gaza and the West Bank, the Gulf War, the war in Bosnia and genocide in Rwanda.
It is small wonder, therefore, that the UN has recognised the need for reform in order to meet the changing demands made upon it.
The UN consists of the General Assembly, the Security Council and the Secretariat. It also includes organisations such as the World Bank, the UN Commission for Human Rights and the International Court of Justice.
The number of workers within the UN amounts to 52,000, of which 4,700 work in the New York secretariat while the rest is scattered throughout the world. Heading the secretariat is Mr Kofi Annan, a Ghanaian who became Secretary General two years ago.
The 185 members of the General Assembly, which meets continuously during the last quarter of each year, concern themselves with matters relating to human rights, education, development economics, the environment and health. The Security Council meets regularly throughout the year and deals primarily with security and peacekeeping. These meetings are held in camera.
The five permanent members of the Security Council - Britain, the US, France, Russia and China - are joined on the council by a further 10 countries who hold their seats for a two-year period. Ireland is one of three countries at present lobbying for two Security Council seats which fall vacant in 2001. (The others are Norway and Turkey.) Ireland's Permanent Representative to the UN, Mr Richard Ryan, arrived in New York via posts in London, Madrid and South Korea.
The UN is financed in three ways: by compulsory assessed contributions towards the regular UN budget, by compulsory assessed contributions towards peacekeeping operations and by voluntary contributions. The question of who pays what towards the cost of peacekeeping has continued to vex member-states. It was an Irish proposal, which, made in 1963 though not adopted at the time, laid the foundation for the way in which future assessments were arrived at.
The UN appears to many in the guise of a world government, keeping tyrants in check, caring for the war weary and enabling emerging countries put into practice the principles of democracy promoted in the UN's own charter. This, of course, is an expression of the idealism and rhetoric which have dogged the UN for so long: for the organisation is nothing more than the sum total of its 185 members, some of whom place democracy and human rights at the bottom of their wish lists.
Every evening at 4.30, a security man begins lowering all 185 of the national flags in front of the UN building. Unusually for the US, where the Stars and Stripes enjoys a superior position, the array of UN flags fly at the same height - for here, on international territory, all countries are equal.
This, of course, is one of the many myths surrounding the UN, for in practice it is one of the most undemocratic institutions in the world; an institution of which one small but powerful part - the Security Council - meets in secret and makes decisions which are binding on the majority and where, within the Security Council itself, decisions are made to take actions the validity of which are open to question.
Mr Annan has made a commitment to reforming the UN but he will have his task cut out to dealing the growing tendency within the Security Council to supplant mediation with military intervention.