International Law

International law is a collection of laws that are accepted as governing the relations between states. There are three types of international law: public international law, private international law, and supranational law. There are also two branches of international law: jus gentium and jus inter gentes. To explore this concept, consider the following international law definition.

Definition of International Law


  1. The collection of rules that nations accept as binding insofar as their interactions with one another.



What is International Law

International law refers to the collection of laws that are accepted between countries as the laws that will govern the activities that they engage in with one another. International laws are established to deal strictly with issues that would concern countries as a whole, rather than focusing on the rights of the individual citizens that live in those countries.

There are two branches of international law: jus gentium and jus inter gentes. Jus gentium is not a statute or legal code, but more of an accepted body of laws that governs the relations between countries. Jus inter gentes, on the other hand, refers to the body of treaties and/or agreements that are mutually acceptable to both countries.

A significant portion of international law is referred to as “consent-based governance.” What this means is that a state is not obligated to abide by the law unless it has given its permission to the specific plan of action. However, there are other aspects to international law that are not consent-based, but that still must be followed by the nations.

Types of International Law

When discussing the laws that govern the activities between nations, there are three types of international law that can be referenced: public international law, private international law, and supranational law.

Public International Law

Public international law is one example of international law, and it deals with those nations and persons that may be affected by those particular laws. Aspects of public international law concern:

  • Customary public international law, which involves regular state practices that rely on opinion juris, which is the belief that an action is carried out because of a legal obligation to do so.
  • Globally accepted standards that govern behavior.
  • Legal codes that are written into agreements referred to as treaties.

Private International Law

Private international law is different from public international law in that it governs private conflicts between individuals, rather than between the states. Private international law determines the jurisdiction that has authority to hear a legal dispute, and which jurisdiction’s laws should be applied to the situation.

Corporations in particular are commonly involved in private international law disputes because they frequently transfer their capital and supplies across international borders. The more business that is carried out between nations, the more likely a dispute will arise.

For instance, if Company A operates in both the U.S. and Canada, and a legal dispute arises, then private international law will determine which country has jurisdiction over the dispute and, consequently, which laws should be taken into account when arguing the facts of the case. This will help the company to understand if its Canada branch or its U.S. branch should be involved in arguing the case.

Supranational Law

Supranational law refers to the situation wherein nations surrender to the court their right to make certain judicial decisions. The decisions made by a court appointed by supranational law take priority over the decisions that are made by national courts. An example of international law that follows the rules of supranational law is that which is represented by the European Union (“EU”), an organization that deals in international treaties and that uses a supranational legal system. The European Court of Justice rules over all of the courts within the member states of the EU in accordance with European Union law.

International Criminal Law

International criminal law is a subsect of public international law that works to punish those who commit crimes of a more severe nature that often attack large groups of people. Examples of crimes that would be handled by international criminal law include:

  • Genocide
  • Crimes against humanity
  • War crimes
  • Crime of Aggression (a specific crime wherein someone plans, begins, or carries out an act of aggression through the use of state military force and that violates the Charter of the United Nations).

To understand international criminal law, it is first important to understand its components. First, international law rules over the relationships between and responsibilities of interacting countries. Next, criminal law establishes what is and is not considered a crime, and then sets up respective punishments for those crimes. International criminal law combines the two by having international law at its core, which dictates the rules, and consequences akin to those that would be suffered by those responsible for committing serious crimes.

International Law Example Involving the Death Penalty

On June 24, 1993, Jose Medellin – a Mexican national who had lived most of his life in the U.S. – took part in a gang initiation with five other men at a park in Houston, Texas. Two additional men were present at the initiation but did not take part in the ritualistic beating of their newest member. Once the initiation was complete, the men stayed in the park, drinking alcohol.

Two teenage girls who had attended a nearby party encountered the group after cutting through the park in order to make it home before curfew. The gang approached the girls and held them down against their will. Two of the men decided to leave at this point. The remaining members of the gang then brutally raped and beat the girls, then decided to kill them so they could not identify their attackers.

The gang then reconvened at the home of Peter Cantu, one of the gang members, where he lived with his brother, Joe, and sister-in-law, Christina. Christina asked why the men were covered in blood, and Medellin proudly recounted the details of what the gang had done, saying that what they did would soon be on the news. He then informed her that he had raped the girls and had killed one of them.

After the gang had left, Christina convinced Joe to report the gang’s crimes to the authorities. Four days later, the girls’ bodies were found. Everyone who was believed to be responsible was arrested, and Medellin gave both written and taped confessions of his crimes. He was sentenced to the death penalty upon the conclusion of his trial.

The case became an example of international law at work when, in the International Court of Justice, Mexico sued the U.S. on behalf of over 50 Mexican citizens who had been given the death penalty without their national consulates being notified. The court ruled that the U.S. had indeed acted in error, and that the defendants’ cases should be reopened.

Initially, the U.S. government felt Mexico’s suit was “unjustified,” “unwise,” and an “ultimately unacceptable intrusion in the United States criminal justice system.” However, after the court’s decision was handed down in 2005, the government reversed its position and announced that it would abide by the decision.

The government then instructed states to reconsider those convictions and sentences pertaining to Mexican nationals who were on death row here in the U.S. Medellin’s death-penalty appeal was one of those cases pending before the Supreme Court, and it was dismissed by the Court in order to enable Texas courts to comply with the government’s directive.

The Texas Court of Criminal Appeals, however, refused to comply, with one of the court’s judges accusing the White House of an “unprecedented, unnecessary and intrusive exercise of power over the Texas court system.” The Bush administration responded by entering the case on Medellin’s behalf and urging the Supreme Court to overturn the Texas court’s decision.

The government’s brief informed the justices that if the Texas court’s decision was not reversed, then it would “place the United States in breach of its international law obligation” to comply with the International Court of Justice’s decision. Further, it would also “frustrate the president’s judgment that foreign policy interests are best served by giving effect to that decision.”

Four of the Supreme Court Justices (Chief Justice Roberts and Justices Scalia, Kennedy, Thomas, and Alito) rejected the arguments made by the Bush administration. Justice Stevens wrote a concurring opinion, and Justices Breyer, Souter, and Ginsburg dissented.

On July 16, 2008, the International Court of Justice asked for stays of the executions of Medellin and four additional Mexican nationals who were in similar situations (their consulates not being notified). The following day, Robert Black – a spokesman for Texas Governor Rick Perry – said the state would proceed with Medellin’s August 5, 2008 execution, despite the International Court of Justice’s order for a stay. Said Black:

“The world court has no standing in Texas and Texas is not bound by a ruling or edict from a foreign court. It is easy to get caught up in discussions of international law and justice and treaties. It’s very important to remember that these individuals are on death row for killing our citizens.”

Medellin was indeed executed at 9:57 p.m. on August 5, 2008, after a three-hour delay while the Supreme Court heard a late appeal, which was ultimately denied anyway.

Related Legal Terms and Issues

  • Consulate – An official who is appointed by the government to live in a foreign city and protect the rights of that government’s citizens who live there.