International Law

International law is a set of rules by which most nations are expected to abide by when interacting with each other, with individuals, and with companies. International law most impacts large companies and individuals who are victims of human rights abuses as well as refugees and asylum seekers.

What is International Law?

International law includes a group of principles, rules, and agreements that govern the interactions between sovereign states (nations), between individuals and states, and between international organizations. There are two main categories of international law:[1]

  1. Public international law. Much of international law concerns the interactions between nations and between nations and individuals. It includes human rights, economics, sea and trade laws, environmental law, diplomacy, and humanitarian law.
  2. Private international law. Increasingly, international law also governs interactions between individuals or corporations. When conflicts between these private entities involve more than one country, they can become subject to international law.

These two areas of international law are not always clearly distinct from each other. The line can be blurred, and in cases involving two individuals or companies, public law may come into play.

What Are the Sources of International Law?

International law comes from both customary and conventional sources. Customary laws are general practices not necessarily written down but accepted by most states. Conventional laws come from formal agreements between nations. These two categories can be broken down further into more specific sources of international law:

  • International agreements. When separate states formally agree on something, it becomes conventional international law. Treaties, conventions, protocols, and covenants come from these agreements.
  • Custom. Customary international laws arise from the regular, consistent practice of certain customs. They do not have to be codified in a document, but many were outlined in the Vienna Convention on the law of treaties.
  • Jus cogens. This Latin term refers to a compelling law or peremptory norm. It is any fundamental principle in international law that cannot be overridden. For instance, this includes prohibitions against slavery, genocide, and human trafficking.
  • International resolutions. In some instances, but not always, a resolution made by an international governing body can become international law. For instance, the United Nations Security Council issued a resolution to sanction states that breach international law in such a way as to threaten peace and security.
  • International tribunals. Likewise, international tribunal, court, and arbitration decisions may direct international law. The United Nations also states that judicial writings can influence or direct international law.

The Main Types of International Law

Many laws recognized internationally mirror those of individual nations. There are main categories of laws that are most important on the international stage:

  • Criminal Law. International criminal law regulates crimes across national boundaries but also the most serious crimes, like genocide, war crimes, and crimes against humanity. International criminal courts and tribunals enforce these laws.
  • Diplomatic Law. Diplomacy is the act of negotiating and resolving disputes between states without resorting to force. International laws govern diplomatic actions through old customary laws.
  • Economic Law. This category impacts both nations and private individuals and companies. These laws govern economic relations, transactions that cross borders, trade, and financial institutions.
  • Environmental Law. Several international treaties, including the Kyoto Protocol and the World Earth Summit, set standards to regulate how nations and international organizations impact the environment. They include laws regarding oceans and fisheries, carbon emissions, polar ice caps, and more.
  • Humanitarian Law. This body of law regulates armed conflicts between nations. It determines the legality of war and its justifications and the conduct of nations during the war. Humanitarian law is one of the older types of conventional international law and includes the initial Geneva Convention of 1864.
  • Human Rights Law. Human rights laws largely arose out of war atrocities. The formation of the United Nations (UN) was instrumental in codifying human rights around the world, although it is not the only organization that has created international human rights laws. Human rights are those of every person in the world, whether or not their nation guarantees those rights. The UN’s Universal Declaration of Human Rights, for instance, states that all people have a right to life, liberty, and security.

The U.S. and International Law

Although international law often refers to states, this does not include the states of the United States. Sovereign states are internationally recognized and have their own governments, populations, and territories. The U.S. Constitution forbids any of the states of the union to engage in international law. That right is strictly reserved for the federal government.

The actions and laws of the U.S. consider international law. Courts make decisions and interpret laws based mostly on U.S. law but also must try to avoid violating agreed-upon international laws.

Interactions with individuals, companies, or governments in other countries can be complicated. International law attempts to govern these interactions, ensuring human rights, humanitarian actions, environmental compliance, and more. If you have a concern about international relations, crimes, or civil actions, you can find a lawyer specializing in international law for guidance.

  1. Cornell Law School. Legal Information Institute. (n.d.). International Law.
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