International law is composed of rules, customs, treatises between and among nations, and decisions by the International Court of Justice, which impact the legal transactions between nations, their governments, businesses, and organizations. The area of international law is continuously evolving, with nations adapting new rules as new customs and treatises arise. Nations are free to adopt or reject international laws, although there are instances when groups of countries pressure other groups of countries to ratify an international law in order to achieve goals that have universal effect.

The United Nations, and its counterpart court, the International Court of Justice, are the most influential organizations in the world with respect to international law. The United Nations regularly convenes to pass so-called conventions to address transnational issues, such as territorial disputes, human trafficking, human rights violation, environmental issues, and business transactions.

There are two types on international law: public and private. Public international law governs the disputes and transactions between nations, while private international law governs the legal disputes between the citizens of different nations.

While international law is difficult to define as a single body of law, there are three principles that govern: (1) principle of comity, (2) act of state doctrine, and (3) doctrine of sovereign immunity. Under the principle of comity, one of two nations who share common public policy ideas submits to the laws and judicial decrees of the other. Under the Act of State Doctrine, nations around the world agreed to respect the sovereignty of a nation in its own territory and agreed not to interfere with official domestic actions. Under the Doctrine of Sovereign Immunity, nations are immune from suits, unless they waive such immunity.

International law is a complicated set of laws that require the interpretation of expert international law attorneys. One of the issues arising from international law would be its enforceability. In cases of U.N. conventions, there are signatory states but not all signatory states ratify the conventions, which means the signatory states agree to the conventions but do not agree to implement the conventions to their national jurisdiction. In fact, the question of enforceability alone has spawned an area of the law where experts are sought after to answer this very specific question.

In the United States, the enforceability of international law is often highlighted in cases when a foreign national is convicted of a criminal offense, or when an American citizen is convicted of a criminal offense in another country. Depending on the agreement between the United States and the country where the convict is a citizen, there might exist an extradition agreement, which will usually provide that the country of the citizen will have jurisdiction over the convict. There might not exist an extradition agreement, and, because a criminal offense is a matter of national security, the country where the American citizen was convicted would not hand over jurisdiction to the United States. It is thus crucial to employ the assistance of an international law attorney as both municipal and international laws are complicated sets of law that need the interpretation of experts.