International Law

I INTRODUCTION

International Law, principles, rules, and standards that govern nations and other participants in international affairs in their relations with one another. International law is the law of the international community. Most international law consists of long-standing customs, provisions agreed to in treaties, and generally accepted principles of law recognized by nations. Some international law is also created by the rulings of international courts and organizations.

The purposes of international law include resolution of problems of a regional or global scope (such as environmental pollution or global warming), regulation of areas outside the control of any one nation (such as outer space or the high seas), and adoption of common rules for multinational activities (such as air transport or postal service). International law also aims to maintain peaceful international relations when possible and resolve international tensions peacefully when they develop, to prevent needless suffering during wars, and to improve the human condition during peacetime.

Enforcement of international law is often difficult because nations are sovereign (independent) powers that may put their own interests ahead of those of the international community. In addition, the mechanisms of enforcement are young and not well developed. Enforcement may be effectively achieved, however, through the actions of individual nations, agencies of international organizations such as the United Nations (UN), and international courts. The United Nations Security Council can authorize economic sanctions, diplomatic sanctions, or military force to maintain or restore international peace and security.

International law began as a system governing the relations among sovereign states, and states have always been the primary legal entities affected by international law. As the global system has become more complex, however, international law has come to recognize and regulate international organizations, businesses, nonprofit entities, and individuals. The emergence of international human rights law and, more recently, international criminal law reflects the fact that individuals today are direct subjects of international law in certain respects.

II ORIGINS

The need for rules of conduct between independent political entities developed along with government in ancient times. Early civilizations established rules governing the conduct of hostilities, the making and observance of treaties, and the treatment of foreign traders, travelers, and diplomats. These rules were often based on ritual and custom. The oldest known treaty, preserved in an inscription on a stone monument, is a peace treaty between two city-states of Sumer, dating from about 2500 bc. The empires of the ancient Middle East concluded a considerable number of treaties between 2000 and 1000 bc concerning topics still debated today, such as the extradition of fugitives and the creation of military alliances.

Later civilizations further developed tenets of international law. Jewish law as set forth in the Old Testament in the Book of Deuteronomy contains prescriptions for the mitigation of warfare, notably prohibitions against the killing of women and children. The Greek city-states had an elaborate treaty system governing many aspects of their mutual relations. In Asia the political units of ancient India and China, during certain periods, also developed and applied international law.

Beginning with the era of the Roman Republic (509 to 27 bc), the Romans made significant contributions to the evolution of international law. They developed the idea of a jus gentium, a body of laws designed to govern the treatment of aliens (noncitizens) subject to Roman rule and the relations between Roman citizens and aliens. They recognized in principle the duty of a nation to refrain from engaging in warfare without a just cause and originated the idea of a just war.

Modern international law began to develop with the rise of national states in Europe after the 15th century, when the basic ideas of national territory and jurisdiction were established. In 1625, building on the work of previous legal writers, the Dutch jurist Hugo Grotius published his celebrated treatise De Jure Belli ac Pacis (On the Law of War and Peace). Grotius argued that existing customs governing the relations between nations had the force of law and were binding unless contrary to natural justice or the law of nature (natural law), an immutable higher law governing all human conduct. Grotius's influence on international affairs and the settlement of wars was great, and he is sometimes called the father of modern international law. His ideas became the cornerstone of the international system as established by the Peace of Westphalia (1648), a treaty that ended the Thirty Years' War.

Other scholars and statesmen further described and developed the basic rules of international law, among them the Dutch jurist Cornelis van Bynkershoek and the Swiss diplomat Emmerich de Vattel. Vattel's book, Le droit des gens (1758; Law of Nations), greatly influenced the framers of the Constitution of the United States with its ideas of natural law governing the behavior of states. Over time scholars gave increasing emphasis to the idea of state sovereignty, so that by the end of the 19th century the theoretical foundation of international law had shifted from natural law to a strictly consensual approach known as positivism. Positivism claims that each nation is bound only by the international rules that it freely accepts to limit its otherwise unlimited freedom of action. The clash between positivists and adherents of natural law continues today. Conflict is most pronounced over the issue of whether there are fundamental “higher norms” of international law, a principle called jus cogens, that sovereign states are obliged to respect.

III THE MODERN SYSTEM

Modern international law stems from three main sources: treaties, customs, and the generally accepted principles of law derived from national legal systems throughout the world. International organizations also play an important role in the formation of international law.

A Treaties

Treaties are written agreements between two or more sovereign states. International organizations may also be given the capacity to make treaties, either with sovereign states or other international organizations. Treaties may be known by many other names—for example, agreement, convention, protocol, pact, and covenant—but the name chosen generally does not affect the legal status of the agreement. As long as the parties intend the text to be binding, it is a treaty. Treaties may incorporate rules of custom or develop new law.

The present system of international law remains largely consensual and centered on the sovereign state. It is within the discretion of each state to participate in the negotiation of, or to sign or ratify, any international treaty. Likewise, each member state of an international organization such as the UN is free to ratify any convention adopted by that organization. Treaty law thus is created by the express will of states.

Treaties and conventions were, until the 20th century, usually bilateral (between two nations), but some multilateral treaties resulted from international conferences held in the 19th century, before permanent international organizations were created. Such conferences played an important part in the development of the international legal system. Noteworthy examples include the Congress of Vienna, which through its Final Act of 1815 reorganized Europe after the defeat of Napoleon and also contributed to the body of international law. It established rules for diplomatic procedure and the treatment of diplomatic envoys. On the urging of Britain, it also included a general condemnation of the slave trade. The Conference of Paris (1856) was convened to terminate the Crimean War. It also adopted the Declaration of Maritime Law that abolished privateering (the use of private ships during war) and letters of marque (licenses given to private citizens to arm ships and attack enemy merchants), modernized the rights of neutrals during maritime war, and required blockades to be effective. The Declaration of Paris also initiated the practice of allowing nations other than the original signatories to accede (become a party to) to an agreement.

In 1864 a conference convened in Geneva, Switzerland, at the invitation of the Swiss government. The conference approved a convention for the proper treatment of wounded soldiers on the battlefield and the protection of medical personnel; many nations subsequently acceded to this convention, the first Geneva Convention. The peace conferences held in 1899 and 1907 in The Hague, the Netherlands, resulted in a number of conventions designed to avoid or mitigate the rigors of war. The 1899 conference adopted a Convention for the Pacific Settlement of International Disputes, which created the Permanent Court of Arbitration in The Hague to settle disputes between nations (see Hague Conferences).

B Customary Law

Customary international law is unwritten and derives from the actual practices of nations over time. To be accepted as law, the custom must be long-standing, widespread, and practiced in a uniform and consistent way among nations. One example of customary international law is a nation's right to use the high seas for fishing, navigation, overflight, and submarines.

Treaties represent another source of customary law. Although treaties generally bind only those countries that ratify them, customs may be deduced from the rules and statements contained in treaties. These new customs may be considered binding even on those states that did not sign and ratify the original treaty. Whether or not they are embodied in a written treaty, customs become part of international law because of continued acceptance by the great majority of nations.

Some customary international law has been codified in recent years. For example, the Vienna Convention on the Law of Treaties, which was approved in 1969 and took effect in 1980, codified the customary law that treaties between sovereign states are binding on their signatories and must be followed in good faith.

C General Principles

The phrase “general principles of law” appeared in the statute of the Permanent Court of International Justice, established in 1921, three years after the end of World War I (1914-1918). The court was directed to decide disputes brought before it on the basis of existing treaty law and customary international law. Some of the diplomats and lawyers drafting the statute of the court feared, however, that disputes might arise over new international issues for which there would be no settled custom or applicable treaty. They decided, and the nations voting for the statute agreed, to add a third source of law—“general principles of law recognized by civilized nations”—to allow the court to draw upon widely recognized legal principles in national law. In this way, the court would not have to refuse to settle a dispute because of the absence of international law. General principles that have been applied by the court and its successor, the United Nations International Court of Justice, include the “clean hands” doctrine (it is improper to accuse someone of misconduct that the accuser has also engaged in), the principle that individuals should not be a judge in their own dispute, and the principle of res judicata (a case that is decided cannot be tried again).

D International Courts and Organizations

Judicial decisions rendered by international courts are important elements in identifying and confirming international legal rules. The most important international courts are the UN International Court of Justice, which mainly handles legal disputes between nations, and the International Criminal Court, which prosecutes individuals for genocide, war crimes, and other serious crimes of international concern. Resolutions and decisions of the UN and other international organizations now also have a great impact on the views and practices of sovereign states, sometimes leading to rapid formation of customary international law. States have given a very few international organizations, such as the European Union and the UN Security Council, the power to enact directly binding measures.

The first international organizations emerged in the 19th century. Technological advances such as the telegraph and the telephone, together with a rise in international trade, created a need for permanent international institutions to regulate problems that exceeded national boundaries. The earliest organizations of this type were specialized bodies such as the International Telegraphic Union (1865) and the Universal Postal Union (1874).

After World War I European countries created the League of Nations, an organization with a general mandate to maintain peace and prevent war. The League's covenant was part of the Treaty of Versailles signed in 1919 to officially end the war. Pursuant to provisions in the covenant, the Permanent Court of International Justice was established in 1921 as the world's first international court. Its role was to decide international disputes that were voluntarily submitted to the court by the nations involved, and to issue advisory opinions on disputes referred to it by the League. Although the court helped to develop international law, its judges were hampered by the lack of universal agreement on many aspects of international law.

The onset of World War II in 1939 proved the League of Nations ineffective in preventing hostilities. Equally unsuccessful was the Pact of Paris, also called the Kellogg-Briand Pact, a multilateral treaty renouncing the use of war that had been signed in 1928 and ultimately ratified by more than 60 nations, including Germany and Japan. After World War II ended in 1945 the United Nations replaced the League of Nations, and the International Court of Justice succeeded the Permanent Court of International Justice.

The United Nations Charter created elaborate machinery for maintaining peace and security and for solving disputes among nations. It also specifically directed the General Assembly to encourage the progressive development and codification of international law. To carry out this task, the General Assembly created two subsidiary organs: the International Law Commission (1947) and the Commission on International Trade Law (1966). Over the years the International Law Commission has prepared drafts of treaties codifying and modernizing a number of important topics of international law, including the law of the sea, diplomatic relations, consular relations, law of treaties between nations, succession of states in respect to treaties, law of treaties between nations and international organizations, immunity of states from the jurisdiction of other states, and the law of international freshwaters. The Commission on International Trade Law drafts texts on laws concerning international commerce and economic development. Upon acceptance by the General Assembly, drafts from the commissions usually are submitted to international conferences called by the UN for adoption of the respective conventions.

In some instances, the UN has organized conferences to discuss major international issues or to negotiate treaties without prior proposal by the International Law Commission. The most important example was the third UN Conference on the Law of the Sea, which terminated its work in 1982. The conference adopted a convention (which came into force in 1994) governing all aspects of the peaceful use of the oceans, including territorial boundaries, navigational rights, and economic jurisdiction (see Freedom of the Seas). Another example is the 1992 UN Conference on Environment and Development, held in Rio de Janeiro, Brazil, and informally known as the Earth Summit. The conference produced two major treaties: the Convention on Biological Diversity, which seeks to preserve the world's biological diversity and promote the sustainable use of its components; and the Framework Convention on Climate Change, which seeks to limit industrial emissions of gases leading to global warming. Sometimes the UN convenes major conferences to assess progress and problems concerning a specific topic, without adopting a new agreement. Such conferences have been held on human rights and on the status of women worldwide.

A landmark in the development of international law occurred in 1998 at a UN diplomatic conference in Rome, Italy, when 120 countries adopted a treaty to establish the world's first permanent international criminal court. Officially established in 2002, the International Criminal Court (ICC) operates independently of the United Nations and has the power to initiate investigations and prosecutions of war criminals, including those accused of genocide, crimes against humanity, and other serious crimes. Unlike previous war crimes tribunals, such as those created in response to atrocities in the former Yugoslavia and in Rwanda, the ICC's jurisdiction is not limited to specific conflicts.

IV INTERNATIONAL LAW AND NATIONAL LAW

Every nation is expected to obey international law. Some nations make international law automatically part of the law of their land. The U.S. Constitution designates ratified treaties, along with the Constitution itself and federal statutes, the supreme law of the land (Article VI) and empowers Congress “to define and punish … Offences against the Law of Nations” (Article I, Section 8). Customary international law is automatically incorporated into the U.S. legal system as federal common or unwritten law.

In cases involving international law, U.S. state and federal courts presume that U.S. law conforms to international law; such an attitude has been urged consistently by the Supreme Court of the United States. In some countries, such as the United Kingdom, treaties do not become effective in national law until they are enacted by Parliament. In other countries, a treaty or customary international law is given constitutional status superior to national legislation. How a sovereign state adopts and applies international law is generally left to its discretion, so long as it conforms to the law in the end.

Whatever the constitution or legal system of a nation, it cannot use its domestic law as an excuse to breach an international agreement or violate an international rule. This was made clear during the war crimes trials held in Nürnberg, Germany, following World War II. The Nürnberg tribunals rejected the defense that certain acts, such as the killing of prisoners of war, were permitted under the domestic laws of Nazi Germany. The tribunals held that such laws were null and void because they contravened the generally valid rules of warfare. It also held that the individuals responsible for issuing and executing such laws were criminally responsible for grave breaches of international law. Today, international human rights courts often declare national laws incompatible with international rules and may award compensation to those whose rights have been violated.

V MATTERS OF INTERNATIONAL CONCERN

The scope of international law is vast. Nearly every matter of legal regulation within a nation has some international counterpart. Over the last century, advances in communications technology, growth in global trade and travel, and the advent of weapons of mass destruction have led to an enormous expansion in the range of topics regulated by international law. In addition to the classic matters of diplomacy, war and peace, trade, and territorial boundaries, international law now covers matters as diverse as environmental protection, human rights, nuclear testing, war crimes, outer space, child custody, recognition of wills and testaments, exchange of prisoners, and protection of archaeological sites and art treasures. This section discusses several major areas of international law, including peace and security, human rights, the environment, and the global commons.

A Peace and Security

Among the central aims of the UN are the maintenance of peace and security and the suppression of acts of aggression. The principles of the UN Charter prohibit the use of force to settle disputes and bar intervention by a nation into the domestic affairs of another nation. The charter also expressly includes among its objectives the maintenance of respect for the obligations arising from treaties and other sources of international law.

International law provides methods for the settlement of disputes by means other than war. The UN Charter directs disputants to engage in negotiation, conciliation, arbitration, or recourse to the International Court of Justice. When conflicts do arise, the UN Security Council may determine that there exists a threat to the peace or a breach of the peace, or that an act of aggression has been committed. The Security Council may vote to deploy UN peacekeeping forces—military personnel and civilians volunteered by UN member governments—to help implement peace agreements, monitor ceasefires, provide emergency relief, and perform other functions essential to maintain peace. Over time the decisions of the Security Council have created a body of law and policy on issues of peace and security, including the development of international criminal law to hold individuals accountable for the most serious illegal acts of violence.

B Human Rights

Since World War II the international community has become increasingly concerned with the protection of human rights. Although concern for human rights is expressed in the UN Charter, the development of specific norms related to human rights began in 1948 with the passage of two nonbinding declarations: the American Declaration of the Rights and Duties of Man, approved by the Organization of American States, and the Universal Declaration of Human Rights, approved by the UN. The Universal Declaration of Human Rights described a variety of rights, including the rights to life, liberty, and security of person; to freedom from slavery; to freedom of conscience, religion, opinion, expression, association, and assembly; to freedom from arbitrary arrest; to a fair and impartial trial; to privacy; and to education. This document remains the cornerstone of international human rights law and has been the basis of bills of rights in nearly 100 countries.

Other important international treaties related to human rights include the Convention on the Prevention and Punishment of the Crime of Genocide (1948); the International Convention on the Elimination of All Forms of Racial Discrimination (1965); the UN Covenant on Civil and Political Rights (1966) and its companion, the Covenant on Economic, Social and Cultural Rights (1966); the Convention on the Elimination of All Forms of Discrimination Against Women (1979); the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment (1984); and the Convention on the Rights of the Child (1989). These treaties have been widely ratified; the Convention on the Rights of the Child, for example, has been accepted by every country in the world except the United States and Somalia. The treaties have been supplemented by three regional human rights agreements: the European Convention for the Protection of Human Rights and Fundamental Freedoms (1950); the American Convention on Human Rights (1969), and the African Charter on Human and Peoples' Rights. The regional agreements and many of the UN treaties allow individuals to bring petitions to regional or global human rights organizations for protection against acts by their governments that violate their rights.

C The Environment

In the late 1960s concern with the state of the world's environment emerged as an international issue. This occurred largely in response to several disastrous spills by oil tankers that brought attention to high pollution levels and the threats they pose to human health and biological diversity.

The UN convened its first environmental conference in 1972 in Stockholm, Sweden, from which emerged the Stockholm Declaration on the Human Environment. The Declaration contains several legal principles that have become the foundation for a vast network of international agreements. The most important principle directs that each state has the sovereign right to use its natural resources, but also has the corresponding duty to ensure that its activities do not cause harm outside its boundaries. Other principles link environmental protection with human rights and emphasize the duty of each person to safeguard the environment. Many modern environmental agreements regulate specific areas (the Baltic Sea, Antarctica), specific species (whales, migratory birds), or specific hazards (nuclear energy, toxic wastes). In each case, the legal obligation that emerges is to protect and preserve components of the environment to foster sustainable development.

D The Global Commons

Large areas of the globe and beyond do not and legally cannot belong to any nation: most of the oceans and their resources, Antarctica, Earth's atmosphere, outer space, and the Moon and other natural objects in space. These areas are known collectively as the global commons. The absence of political sovereignty for these areas means that international regulation is required to avoid conflict over them and to protect them from overuse, pollution, and other harm. International agreements for these areas are generally accepted as providing the legal framework for all those who conduct activities in them. See Aviation Law; Maritime Law; Freedom of the Seas.

E Other Issues

International law has no fixed content. New threats that cannot be addressed or resolved by a single nation constantly call for new international responses. For example, recent international agreements aim to combat terrorism, the distribution of illicit drugs across national boundaries, and the spread of infectious disease. The development of new technologies, such as the Internet, can also lead to the creation of new international legal frameworks.

See also International Relations; Treaty.

Contributed By:

Dinah Shelton

United Nations Security Council

The Security Council is the most powerful body in the United Nations (UN). Its 15 members determine how the UN should resolve world conflicts, and it is the only UN body that can order enforcement action in the event of aggression. The Council's five permanent members—Britain, China, France, Russia, and the United States—have the most power because any one of them can veto a Council decision.

Reuters/Jeff Christensen