International treaties, moral and state practices and judicial decisions are important sources of international law. The origins of international law date back to antiquity. Early examples include the peace treaties between the Mesopotamian city-states of Lagash and Umma (circa 2100 BC) and an agreement between the Egyptian pharaoh Ramses II and the Hittite king Hattusilis III, concluded in 1258 BC. Intergovernmental pacts and agreements of all kinds have also been negotiated and concluded by communities around the world, from the Eastern Mediterranean to East Asia. The International Law Commission was established by the General Assembly in 1947 to promote the progressive development and codification of international law. The Commission is composed of 34 members who collectively represent the principal legal systems of the world and act as experts in their individual capacity rather than as representatives of their Governments. They deal with matters relating to the regulation of relations between States and frequently consult with the International Committee of the Red Cross, the International Court of Justice and the specialized agencies of the United Nations, as appropriate. The Commission also frequently prepares drafts on certain aspects of international law. Since states are numerically few, diverse and atypical, inaccusable, without centralized sovereign power and its agreements are uncontrolled and decentralized, then, according to Wight, “international society is not a society at all. The state of international relations can be described as international anarchy; The Charter of the United Nations empowers the General Assembly to undertake studies and make recommendations to promote the development and codification of international law.
Many subsidiary bodies of the General Assembly deal with specific areas of international law and report to the plenary. Most legal matters are referred to the Sixth Committee, which then reports to the plenary. The International Law Commission and the United Nations Commission on International Trade Law report to the General Assembly. The General Assembly also considers issues related to United Nations institutional law, such as the adoption of the Staff Regulations and the establishment of the internal justice system. Since international law exists in a legal environment without a global “sovereign” (i.e., an external power capable and willing to uphold international norms), the “application” of international law is very different from the domestic context. In many cases, the application takes on coasic characteristics when the standard is self-applied. In other cases, deviating from the norm can pose a real risk, especially if the international environment changes. If this happens, and if enough States (or enough powerful States) constantly ignore a particular aspect of international law, the norm may in fact change according to the concepts of customary international law. Thus, unrestricted submarine warfare before World War I was considered a violation of international law and allegedly a casus belli for the United States` declaration of war on Germany. During World War II, however, the practice was so widespread that during the Nuremberg trials, charges against German Admiral Karl Doenitz for ordering unrestricted submarine warfare were dropped, even though the activity was a clear violation of the Second London Naval Treaty of 1936. Traditionally, sovereign States and the Holy See have been the sole subjects of international law. With the proliferation of international organizations in the last century, they have also been recognized as concerned parties in some cases.
Recent interpretations of international human rights law, international humanitarian law and international trade law (e.g. The measures in Chapter 11 of the North American Free Trade Agreement (NAFTA) have targeted businesses and even individuals. The Dutch jurist Hugo Grotius (1583-1645) is widely regarded as the most founding figure in international law and was one of the first scholars to articulate an international order consisting of a “society of states” governed not by force or war, but by laws, mutual agreements and real customs.  Grotius secularized international law and organized it into a global system; His 1625 work, De Jure Belli ac Pacis (On the Law of War and Peace), established a system of principles of natural law that bound all nations independently of local customs or laws. He also highlighted the freedom of the high seas, which is not only relevant to the growing number of European states exploring and colonizing the world, but is still a cornerstone of international law today. Although the modern study of international law did not begin until the beginning of the 19th century, it was not until the beginning of the 19th century. The 16th century scholars Gentili, Vitoria and Grotius laid the foundations and are widely regarded as the “fathers of international law”.  The field of international law covers a wide range of issues of international concern, such as human rights, disarmament, international crime, refugees, migration, nationality issues, treatment of prisoners, use of force and war.