International law is shaped by the mutual consent of nations, given either by international practice or by treaty agreement. Such practices and agreements may involve only two nations (bilateral agreements) or may extend to many nations (multilateral agreements). As in U.S. contract law, international agreements create laws for the parties to the agreement.
Customary law and laws promulgated by international agreements (such as those adopted by the United Nations) have the same authority as international law. Private or public parties can assign higher priority to one of the sources by agreement. The General Assembly is composed of representatives of each UN Member State and is the main deliberative body on matters related to international law. In fact, many multilateral treaties are adopted by the General Assembly and, subsequently, open for signature and ratification.
The Legal Commission (Sixth) assists in the work of the General Assembly by providing advice on substantive legal issues. The Committee is also composed of representatives of all UN Member States. International law is the term given to the rules governing relations between states. Since most international law is governed by treaties, it is generally up to individual nations to enforce the law.
However, there are some international organizations that enforce certain treaties. The most notable example is the United Nations Organization, which has 192 member states. The most important and concrete sources of international law are bilateral and multilateral treaties. Multilateral treaties are generally prepared during lengthy negotiations in state diplomatic conferences, where a final text of the treaty is adopted and then opened for signature and ratification by states.
When an agreed number of states have ratified the treaty, it enters into force and becomes binding on member states. They address issues relevant to the regulation of relations between states and consult frequently with the International Committee of the Red Cross, the International Court of Justice and United Nations specialized agencies, depending on the topic. The International Law Commission promotes the progressive development of international law and its codification. In this scenario, not only politicians but also international lawyers will argue in legal terms whether the use of force against a (supposedly) imminent terrorist attack that has not yet occurred can be justified as a form of “preventive” self-defense.
Consequently, the discussion has shifted from “whether international law is really law” to “how international norms matter”. While bilateral treaties or treaties between only a few States may best resemble a contract between individuals, multilateral treaties such as the United Nations Convention on the Law of the Sea are often referred to as “legislative treaties” in the sense that they represent, insofar as the legal order international is approaching, international law. Ancient Greece, which developed basic notions of governance and international relations, contributed to the formation of the international legal system; many of the first recorded peace treaties were concluded between Greek city-states or with neighboring states. It is a controversial question in international law whether a territorial entity obtains the legal status of a sovereign state based solely on a series of factual criteria (such as the existence of a population, territory, effective government and capacity to enter into international relations) or whether this also requires a formal recognition by other states.
An active process of transnational socialization — national, regional and international — takes place here, mainly, by States, international organizations and networks of regulatory entrepreneurs. Much of the development and codification of this set of laws is the merit of the International Committee of the Red Cross, founded in 1863 by Henry Dunant, which is a private humanitarian institution based in Geneva and is part of the International Red Cross and Red Crescent Movement. International law establishes the framework and criteria for identifying States as the main actors in the international legal system. In some cases, domestic courts may rule against a foreign State (the realm of private international law) for an injury, although this is a complicated area of law where international law intersects with domestic law.
The theory of international law encompasses a variety of theoretical and methodological approaches used to explain and analyze the content, formation and effectiveness of international law and institutions and to suggest improvements. International law can also be reflected in international courtesy, the practices and customs adopted by states to maintain good relations and mutual recognition, such as greeting the flag of a foreign ship or enforcing a foreign legal judgment. International law is also used to govern issues related to the global environment, global commons, such as international waters and outer space, global communications and world trade. International treaties, State custom and practice, and judicial decisions are important sources of international law.