The development of International Law is one of the primary goals of the United Nations. The Charter of the United Nations, in its Preamble, sets the objective "to establish conditions under which justice and respect for the obligations arising from treaties and other sources of international law can be maintained".
International Law defines the legal responsibilities of States in their conduct with each other, and their treatment of individuals within State boundaries. Its domain encompasses a wide range of issues of international concern such as human rights, disarmament, international crime, refugees, migration, problems of nationality, the treatment of prisoners, the use of force, and the conduct of war, among others. It also regulates the global commons, such as the environment, sustainable development, international waters, outer space, global communications and world trade.
More than 500 multilateral treaties have been deposited with the Secretary-General of the United Nations. Many other treaties are deposited with governments or other entities.
Many multilateral treaties are adopted by the General Assembly and subsequently opened for signature and ratification by Member States of the United Nations.
The International Law Commission was established by the General Assembly in 1948 with a mandate to undertake the progressive development and codification of international law under article 13(1)(a) of the Charter of the United Nations. As an expert legal body, its task is to prepare draft conventions on subjects, which have not yet been regulated by international law and to codify rules of international law in fields, where there already has been extensive State practice. The Commission's work in criminal law led to the adoption of the Statute of the International Criminal Court (ICC). It also drafted the Vienna Convention on Diplomatic Relations (1961) and the Vienna Convention on the Law of Treaties (1969), among others.
Treaties and other international legal instruments are also developed by the specialized agencies of the United Nations, such as the International Labour Organization (ILO), the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO), by the subsidiary organs of the United Nations, such as the United Nations Commission on International Trade Law (UNCITRAL) and the United Nations Office on Drugs and Crime (UNODC), and by multilateral negotiating bodies, such as the Conference on Disarmament.
To become party to a treaty, a State must express, through a concrete act, its willingness to undertake the legal rights and obligations contained in the treaty - it must "consent to be bound" by the treaty. This is usually accomplished through signature and ratification of the treaty, or if it's already in force, by accession to it.
Each year, the UN holds a Treaty Event, highlighting a group of treaties, as a way to encourage Member States to sign, ratify or otherwise support these treaties.
Legal disputes between States can be referred to the International Court of Justice, the principal judicial organ of the United Nations, which also gives advisory opinions on legal questions referred to it by duly authorized international organs and agencies.
The international community has long aspired to create a permanent international court to try the most serious international crimes, and, in the 20th century, it reached consensus on definitions of genocide, crimes against humanity and war crimes.
In the 1990s, after the end of the Cold War, tribunals such as the International Criminal Tribunals for the former Yugoslavia (ICTY) and for Rwanda (ICTR) were established to fight impunity by trying crimes committed within a specific time-frame and during a specific conflict.
In 1998, the international community reached an historic milestone when 120 States adopted the Rome Statute, the legal basis for establishing the permanent International Criminal Court. The ICC is an independent international organization, and is not part of the United Nations system. Its seat is at The Hague in the Netherlands.