Table of Contents
What Is International Law?
International law is the body of legal rules, principles, and institutions that governs relationships involving states, international organizations, and, in certain circumstances, individuals and other non-state actors. Unlike domestic law, which operates primarily within the territory of a particular country and is created and enforced through that country’s governmental institutions, international law regulates conduct across national borders and addresses matters that affect the international community as a whole.
International law governs subjects ranging from treaties, diplomatic relations, and the use of force to international trade, human rights, environmental protection, the law of the sea, international criminal responsibility, and the treatment of refugees. It is therefore not a single, unified statute or code. Rather, it is a complex legal system composed of rules derived from several different sources and administered through numerous international and domestic institutions.
The concept can initially seem paradoxical. States are sovereign, and there is no world government with exactly the same powers as a national government. Nevertheless, states routinely enter into binding agreements, recognize legal obligations toward one another, participate in international institutions, and accept procedures for resolving international disputes. International law provides the legal framework through which these relationships operate.
The Cornell Law School Legal Information Institute’s Wex explanation of international law provides a useful starting point for understanding the field and its principal sources.
Need Official Legal Templates or Documents?
Access attorney-reviewed, fully editable Word (.docx) contracts and printable PDF guides formatted for immediate legal protection.
- ✓ Fully Editable: Includes Word (.docx) & printable PDF
- ✓ Key Clauses: IP transfer, non-solicitation, indemnification & remedies
- ✓ Practitioner Guide: Includes line-by-line filling instructions
Select the specific document below that best fits your requirements:
The Basic Meaning of International Law
At its simplest, international law can be understood as law governing relations beyond the boundaries of a single state.
The phrase, however, requires some qualification.
International law traditionally focused primarily on relationships between sovereign states. A treaty between two countries, for example, may establish rules governing trade, extradition, taxation, diplomatic relations, or the treatment of their nationals. A multilateral treaty may establish obligations among dozens or even hundreds of countries.
Modern international law is broader. International organizations such as the United Nations and its specialized agencies play important roles in the creation and administration of international legal rules. Individuals may also possess rights under international law, particularly in the field of international human rights law, and individuals may bear direct responsibility under international criminal law.
Consequently, international law today governs a much wider range of actors and subjects than the traditional concept of relations between states might suggest.
It is important, nevertheless, not to confuse international law with every rule or practice that crosses a national border. International relations, diplomacy, international politics, and international law overlap, but they are not identical.
A political commitment is not necessarily a legal obligation. A diplomatic statement is not necessarily a legal rule. An international organization may issue recommendations that influence state behavior without those recommendations themselves constituting binding law.
The central question is therefore not simply whether conduct is international. The question is whether a recognized source of international law establishes a legal rule governing that conduct.
Why Does International Law Exist?
States are politically independent and possess sovereignty over their territories. Yet no state exists in complete isolation.
Countries trade with one another, exchange diplomats, share borders, use international waterways and airspace, cooperate against crime and terrorism, address environmental problems, participate in international organizations, and interact with foreign citizens and companies.
Many of the most important problems facing states cannot be effectively addressed by one country acting alone.
Consider climate change. A country can regulate emissions within its own territory, but greenhouse gases do not respect political boundaries. Similarly, international shipping requires rules governing vessels traveling between jurisdictions. International aviation requires cooperation concerning airspace and aircraft operations. International commerce requires legal rules addressing transactions between parties located in different countries.
International law provides a framework for such cooperation.
It also performs another important function: it establishes standards concerning how states may exercise power.
Rules governing the use of force, diplomatic immunity, treatment of prisoners of war, human rights, territorial boundaries, and international crimes all impose legal limitations on conduct that might otherwise be determined solely by political or military power.
International law therefore serves both coordinating and regulatory functions.
It enables states to cooperate, while also establishing legal limits on what states and other international actors may lawfully do.
International Law and Domestic Law
One of the most important distinctions in legal education is the difference between international law and domestic law.
Domestic law is the law operating within a particular state. It includes constitutional law, criminal law, contract law, property law, family law, administrative law, and other branches of national law.
Domestic law is generally created through institutions recognized by the country’s constitutional system. Depending on the legal system, these may include legislatures, courts, executive authorities, administrative agencies, and other governmental institutions.
International law operates differently.
There is no single international legislature equivalent to the United States Congress, the Parliament of the United Kingdom, or the legislature of another individual state. There is also no universal international executive government possessing general authority over every country.
Instead, international law develops through several recognized processes, including treaties, customary international law, general principles of law, judicial decisions, and scholarly writings used as subsidiary means for determining legal rules.
This difference does not mean that international law is merely political or non-binding. It means that the international legal system has a different institutional structure from domestic legal systems.
A treaty may impose binding obligations upon states that become parties to it. Customary international law may bind states independently of a written treaty. International courts and tribunals may exercise jurisdiction when states have accepted that jurisdiction or when another applicable legal basis exists.
The architecture is different, but the existence of legal obligations does not depend upon international law having exactly the same institutions as domestic law.
Who Are the Subjects of International Law?
Traditionally, states were regarded as the principal subjects of international law.
A state generally possesses territory, a permanent population, a government, and the capacity to enter into relations with other states. Statehood is a complex subject in its own right, particularly where disputed territories, governments in exile, or contested claims to independence are involved.
States remain the central actors in international law because they possess sovereignty and are responsible for many of the obligations recognized by the international legal system.
Modern international law, however, recognizes a broader range of participants.
International Organizations
International organizations can possess international legal personality and can exercise rights and obligations under international law.
The United Nations is the most prominent example. Other organizations operate within specialized fields, including international health, aviation, trade, labor, finance, and maritime affairs.
Their legal powers depend upon their constituent instruments and the rules of international law governing international organizations.
Individuals
Individuals historically occupied a secondary position in international law because international law primarily regulated relations between states.
That understanding has changed substantially.
Modern human rights law recognizes individuals as holders of internationally protected rights. International criminal law can also impose responsibility directly upon individuals for certain international crimes.
Genocide, crimes against humanity, war crimes, and aggression are among the offenses addressed by modern international criminal law.
This development is significant because it demonstrates that international law is no longer exclusively concerned with governments dealing with other governments.
Other Actors
International law may also interact with multinational corporations, non-governmental organizations, armed groups, indigenous peoples, and other entities.
Their status differs considerably from that of states, however. Not every international actor is a full subject of international law in the same sense as a sovereign state.
The legal personality, rights, duties, and capacity of each actor depend upon the particular rules applicable to it.
The Main Sources of International Law
International law does not originate from one comprehensive international code.
A central reference point for identifying its sources is Article 38 of the Statute of the International Court of Justice, which identifies several categories of law applied by the Court.
These include:
- international conventions or treaties;
- international custom;
- general principles of law recognized by civilized nations; and
- judicial decisions and the teachings of highly qualified publicists as subsidiary means for determining rules of law.
The terminology of Article 38 reflects the historical language of the instrument and is often discussed critically in modern scholarship. Nevertheless, it remains one of the most important starting points for understanding the sources of international law.
Treaties and International Agreements
A treaty is a formal international agreement that creates legal obligations for the parties according to international law.
Treaties can be bilateral, involving two states, or multilateral, involving many states.
They cover an enormous range of subjects.
For example, treaties may regulate:
- international trade;
- extradition;
- taxation;
- diplomatic relations;
- environmental protection;
- human rights;
- maritime boundaries;
- international aviation;
- arms control;
- refugee protection;
- international criminal cooperation; and
- the peaceful settlement of disputes.
Treaties are particularly important because they provide states with a formal mechanism for expressing consent to specific legal obligations.
A state generally becomes bound by a treaty according to the procedures applicable to that treaty and under the rules governing treaties.
Treaty law itself is also governed by international law. The Vienna Convention on the Law of Treaties is one of the central instruments in this area.
Customary International Law
Not all international law is written in treaties.
Customary international law develops from general and consistent state practice followed because states believe that the practice is legally required. This belief is commonly described by the Latin expression opinio juris.
Two elements are therefore traditionally associated with customary international law:
State practice — what states actually do; and
Opinio juris — the belief that the conduct is carried out because international law requires or permits it.
Customary international law can be particularly important where no treaty governs a particular question or where a customary rule exists independently of a treaty.
Determining whether a customary rule exists can be difficult. Courts and scholars may examine diplomatic statements, legislation, military manuals, judicial decisions, official government positions, treaty practice, and other evidence of state conduct and legal belief.
Custom is therefore not simply a matter of habit.
A practice does not become international law merely because states have followed it for a long time. The legal character of the practice must be established according to the requirements of customary international law.
General Principles of Law
International law also recognizes general principles of law.
These principles can help courts resolve legal questions where treaty and customary rules do not provide a complete answer.
The concept is sometimes associated with fundamental principles common to major legal systems, such as principles concerning good faith, procedural fairness, responsibility, or the administration of justice.
The precise scope and methodology of this source remain subjects of considerable legal scholarship.
General principles should not simply be treated as whatever a court considers morally desirable. Their use as a source of international law is constrained by legal methodology and the relevant international instruments.
Judicial Decisions and Legal Scholarship
Judicial decisions and the writings of highly qualified scholars are generally regarded as subsidiary means for determining rules of international law rather than primary sources equivalent to treaties or customary international law.
International courts and tribunals play an important role in clarifying the meaning and application of international legal rules.
The International Court of Justice (ICJ), for example, decides disputes between states and provides advisory opinions on legal questions referred to it by authorized international institutions.
Other international tribunals specialize in particular areas, such as the law of the sea, international criminal law, and regional human rights law.
Judicial decisions do not automatically create a universally binding rule in the same way that legislation can operate within a domestic legal system. Their precedential effect depends upon the applicable legal framework.
Nevertheless, international judicial decisions are enormously important because they explain how legal principles are interpreted and applied.
Scholarly writings similarly help identify, organize, and analyze international legal rules.
The United Nations and International Law
The United Nations occupies a central position in the modern international legal system.
Its creation after the Second World War represented a major development in international institutional law.
The United Nations Charter establishes fundamental principles concerning international relations, including sovereign equality, peaceful settlement of disputes, and restrictions concerning the use of force.
The United Nations also provides institutional mechanisms through which states cooperate on matters such as peace and security, human rights, development, humanitarian assistance, and international law.
The Security Council has particularly significant powers under the Charter in matters concerning international peace and security.
It is important, however, not to describe the United Nations simply as a world government.
The United Nations is an international organization created by states. Its powers derive from its constituent instruments and applicable international law. It does not possess unlimited authority over sovereign states.
This distinction is essential for understanding the constitutional structure of international relations.
The Role of the International Court of Justice
The International Court of Justice is the principal judicial organ of the United Nations.
Its role is frequently misunderstood.
The Court does not function as a universal supreme court for all legal disputes occurring anywhere in the world. Its contentious jurisdiction concerns disputes between states, and its jurisdiction depends upon a recognized basis of state consent.
The Court can also issue advisory opinions when the relevant United Nations organs or specialized agencies are authorized to request them.
The ICJ has contributed substantially to the development and clarification of international law through its judgments and advisory opinions.
Its decisions have addressed issues including territorial sovereignty, maritime boundaries, diplomatic protection, state responsibility, genocide, the use of force, and treaty interpretation.
Is International Law Really “Law”?
One of the oldest debates surrounding international law concerns whether it should be considered law at all.
The question arises because international law lacks some of the institutional characteristics associated with domestic legal systems.
There is no universal world police force. There is no single global legislature capable of passing laws binding every state. International courts generally require a legal basis for their jurisdiction. Enforcement can be politically and institutionally difficult.
Nevertheless, these characteristics do not logically establish that international law is not law.
Domestic legal systems themselves contain different forms of enforcement and different degrees of institutional authority. Moreover, international law contains recognized sources, established rules, institutions for dispute settlement, procedures for treaty formation and interpretation, doctrines of state responsibility, and mechanisms through which violations may produce legal consequences.
States also routinely behave as though international legal obligations matter.
Governments invoke treaties in diplomatic disputes. Courts interpret international agreements. States protest alleged violations of international law. Governments justify their conduct by reference to international legal rules. International tribunals issue judgments and awards. Treaties are negotiated precisely because states intend to create legal obligations.
The existence of political power and imperfect enforcement does not eliminate the legal character of these rules.
A more accurate question is therefore not whether international law resembles domestic law perfectly, but how a decentralized international legal system creates, identifies, interprets, and enforces legal obligations without a single sovereign authority above the states.
That question lies at the heart of international legal theory.
Enforcement of International Law
International law does not have one universal enforcement mechanism.
Enforcement can occur through several channels.
Diplomatic Measures
States may protest violations, withdraw cooperation, suspend diplomatic relations, or take other diplomatic measures.
International Dispute Settlement
Where jurisdiction exists, states may bring disputes before international courts or arbitral tribunals.
Economic and Political Measures
International organizations and states may impose sanctions or other measures under applicable legal authority.
Domestic Courts
Domestic courts sometimes apply international treaties, customary international law, or other international legal rules, depending upon the constitutional structure of the state.
State Responsibility
A state that commits an internationally wrongful act may incur international responsibility and may be required, depending upon the circumstances, to cease the wrongful conduct, provide assurances against repetition, or make appropriate reparation.
International Criminal Responsibility
In certain circumstances, individuals may be prosecuted for international crimes.
These mechanisms demonstrate an important feature of international law: enforcement is distributed rather than centralized.
Free Presentation
Promissory Estoppel
When a promise binds, even without a deal.
A short, downloadable slide deck explaining this term in depth โ free to open this week, no account needed.
Open This Week's Presentation โAll-Access subscribers get the entire growing library, any time โ see the full catalog.
That decentralized structure is one of the defining characteristics of the international legal order.
International Law and State Sovereignty
State sovereignty is one of the foundational concepts of international law.
Sovereignty generally refers to a state’s authority over its territory and its independence from the authority of other states.
International law simultaneously recognizes sovereignty and imposes legal obligations upon sovereign states.
This is not necessarily a contradiction.
Sovereignty does not mean that a state is legally entitled to do absolutely anything it wishes. States exercise sovereignty within an international legal system that establishes rules concerning their relationships with one another.
Indeed, much of international law can be understood as the legal structure through which sovereign states coordinate the exercise of their powers.
A state may voluntarily enter into a treaty and thereby assume international obligations. It may also be bound by applicable customary international law.
The resulting relationship can be understood as a form of legally structured coexistence: states retain sovereignty while accepting that sovereignty operates within an international legal order.
Public International Law and Private International Law
Another important distinction is between public international law and private international law.
Public international law is what is usually meant when lawyers simply refer to “international law.” It concerns legal relationships among states and other international actors and includes subjects such as treaties, human rights, international criminal law, international humanitarian law, and the law of the sea.
Private international law, by contrast, addresses legal problems arising from private relationships that have connections with more than one legal system.
For example, imagine that:
- a company in France enters into a contract with a company in Japan;
- the contract is performed partly in Germany;
- a dispute is brought before a court in another country.
Which country’s law governs the contract?
Which court has jurisdiction?
Should a judgment from one country be recognized and enforced in another?
These are classic private international law questions.
In the United States, the subject is often described as conflict of laws, while other legal systems commonly use the term private international law.
The distinction is important because the two fields address fundamentally different legal problems even though both involve international elements.
International Human Rights Law
One of the most important developments in modern international law has been the expansion of international human rights law.
Historically, the treatment of individuals within a state’s territory was often regarded as primarily a matter of domestic jurisdiction.
The modern international human rights system changed this understanding.
International treaties and institutions now establish numerous protections concerning matters such as:
- life and physical integrity;
- freedom from torture;
- equality and non-discrimination;
- freedom of expression;
- freedom of religion;
- fair trial rights;
- political participation;
- privacy;
- social and economic rights; and
- protection of children.
Different international and regional systems provide different mechanisms for protecting these rights.
The development of international human rights law illustrates how international law has moved beyond its traditional focus on relationships exclusively between governments.
International Humanitarian Law
International humanitarian law governs conduct during armed conflict.
It seeks to limit the effects of war by establishing rules concerning the treatment of persons who are not, or are no longer, participating in hostilities and by restricting certain methods and means of warfare.
The Geneva Conventions and their Additional Protocols form central components of this legal framework.
International humanitarian law addresses issues including:
- treatment of prisoners of war;
- protection of civilians;
- treatment of wounded and sick persons;
- protection of medical personnel and facilities;
- rules concerning methods and means of warfare; and
- protection of certain cultural and humanitarian interests.
International humanitarian law therefore does not make war lawful merely because particular rules are followed. Rather, it regulates conduct in situations in which armed conflict exists.
This distinction between the legality of resorting to force and the legality of conduct during armed conflict is fundamental.
International Criminal Law
International criminal law concerns individual responsibility for particularly serious crimes recognized under international law.
Its development reflects the principle that individuals, rather than states alone, can bear responsibility for certain acts of extraordinary gravity.
Modern international criminal law commonly addresses crimes such as:
- genocide;
- crimes against humanity;
- war crimes; and
- the crime of aggression.
The International Criminal Court (ICC) is one of the best-known institutions in this field.
International criminal law should not be confused with ordinary criminal law involving an international element. A crime committed by a foreign national, for example, does not automatically become an international crime.
International crimes involve particular legal definitions and conditions established by applicable international law.
International Law and Globalization
Globalization has made international law increasingly relevant to ordinary economic and social activity.
Businesses operate across borders. Digital information can travel between countries almost instantaneously. Individuals work and live in multiple jurisdictions. Goods may be designed in one country, manufactured in another, financed elsewhere, and sold throughout the world.
As a result, legal questions increasingly cross national boundaries.
International law contributes to the framework governing:
- international commerce;
- investment;
- transportation;
- telecommunications;
- environmental protection;
- migration;
- maritime activity;
- international taxation;
- intellectual property;
- cross-border crime; and
- international dispute resolution.
The increasing interconnectedness of states therefore does not eliminate the importance of national law. Instead, it creates more situations in which domestic and international legal systems interact.
International Law Is Not the Same as Global Government
A common misconception is that international law represents an embryonic world government.
That is not an accurate description.
International law does not eliminate state sovereignty or replace national governments.
Instead, it creates a legal framework within which sovereign states and other international actors interact.
The international system remains decentralized. States retain their governments, courts, legislatures, territories, citizenship systems, and constitutional arrangements.
International law operates alongside these domestic systems.
In some circumstances, international rules may be incorporated into domestic law. In others, domestic constitutional law determines how international obligations operate internally.
The relationship between international and domestic law therefore varies significantly between legal systems.
Why International Law Matters to Ordinary People
International law may initially appear to concern only diplomats, governments, and international organizations.
In reality, its effects can reach ordinary individuals in many ways.
International treaties can affect travel, aviation, employment, taxation, extradition, family relationships, trade, immigration, human rights, and criminal cooperation.
International environmental agreements can influence national environmental legislation. Human rights treaties can influence domestic courts and governments. Trade agreements can affect the availability and price of goods. Rules governing international transportation can affect the way people travel around the world.
Even when an individual never appears before an international court, international law may form part of the legal background governing their rights and obligations.
The Relationship Between International Law and National Courts
National courts are important participants in the operation of international law.
Courts may be required to interpret treaties, determine whether customary international law applies, or decide whether an international legal rule has effect within the domestic legal system.
The precise approach differs from country to country.
Some legal systems give certain treaties direct domestic effect after ratification. Others require additional legislation before treaty obligations become enforceable as domestic law.
The United States, for example, distinguishes between treaties and other forms of international agreement and contains constitutional rules concerning the relationship between federal law and international obligations.
Other countries follow different constitutional models.
Consequently, the question “Is this rule international law?” is different from the question “Can I rely on this rule directly in a particular national court?”
The first concerns international legal validity.
The second concerns domestic legal effect.
Keeping these questions separate is essential.
The Dynamic Nature of International Law
International law is not static.
New treaties are negotiated. Existing treaties are interpreted. State practice changes. International courts develop jurisprudence. New international institutions emerge. Technological developments create legal problems that earlier generations could not have anticipated.
Cyber operations, artificial intelligence, climate change, biotechnology, autonomous weapons, space activity, and transnational digital commerce all raise questions concerning the application and development of international law.
Some areas develop rapidly through treaties and international practice. Others remain deeply contested.
International law is therefore both an established legal system and an evolving one.
Its development reflects a continuing tension between competing principles: sovereignty and international cooperation, national interests and collective interests, security and individual rights, stability and change.
International Law as a Legal System
International law is best understood not as a single collection of rules but as a legal system.
It contains:
- sources of law;
- legal subjects;
- institutions;
- rights and obligations;
- interpretive principles;
- procedures for dispute settlement;
- rules concerning state responsibility;
- mechanisms for individual criminal responsibility;
- specialized legal regimes; and
- relationships with domestic legal systems.
Its structure differs from that of domestic law because the international community is decentralized.
There is no single sovereign authority capable of exercising general legislative, executive, and judicial power over the entire world.
Yet international law provides an organized framework through which states and other international actors create, recognize, interpret, and apply legal rules.
That distinction is perhaps the most important conceptual point for a beginner to understand.
International law is not simply “law between countries.” It is a complex body of rules governing an increasingly broad international community.
What Are the Main Areas of International Law?
International law encompasses numerous specialized fields.
Important areas include:
Law of treaties — rules governing the formation, interpretation, application, amendment, and termination of treaties.
State responsibility — rules concerning the legal consequences of internationally wrongful acts by states.
International human rights law — rules protecting internationally recognized human rights.
International humanitarian law — rules governing conduct during armed conflicts.
International criminal law — rules establishing individual responsibility for certain international crimes.
Law of the sea — rules concerning maritime zones, navigation, natural resources, and marine jurisdiction.
International environmental law — rules addressing environmental problems that cross national borders or affect the international community.
International trade law — rules governing international trade relationships and institutions.
International investment law — rules concerning certain cross-border investments and relationships between investors and states.
Diplomatic and consular law — rules governing diplomatic missions, consular functions, privileges, and immunities.
International air and space law — rules governing international aviation and activities in outer space.
Refugee and migration law — international rules concerning refugees, asylum, and related forms of protection.
Each of these areas has its own treaties, institutions, doctrines, and specialized terminology, but they remain connected through the broader structure of international law.
Key Takeaways
International law is the body of legal rules governing relationships among states and other actors in the international community.
Its principal characteristics include:
- It operates across national borders.
- States remain its central actors, but individuals and international organizations also have important roles.
- It is not contained in a single international code.
- Treaties and customary international law are among its principal sources.
- General principles of law and judicial decisions also play important roles in determining and interpreting international law.
- The international legal system is decentralized and does not have a single world government.
- International law can create binding obligations even though its enforcement mechanisms differ from those of domestic law.
- International courts generally exercise jurisdiction on the basis of applicable legal authority, often involving state consent.
- International law interacts with domestic legal systems, but international obligations and domestic enforceability are not always the same question.
- Modern international law extends beyond relations between states to areas such as human rights and international criminal responsibility.
- Public international law and private international law address different categories of international legal problems.
Frequently Asked Questions
Is international law really law?
Yes. International law is generally understood as a genuine legal system consisting of recognized sources, legal rules, institutions, procedures, rights, and obligations. Its decentralized structure and enforcement mechanisms differ from those of domestic law, but those differences do not make it merely political.
Who makes international law?
No single institution makes all international law. States create treaties, state practice contributes to customary international law, general principles may provide additional legal rules, and international courts and tribunals help interpret and apply those rules.
Can international law bind a country?
Yes. A state may become bound by treaty obligations and may also be subject to applicable customary international law and other international legal rules.
Can individuals be bound by international law?
Yes. Although international law traditionally focused on states, modern international law can impose obligations and responsibilities directly upon individuals, particularly in the field of international criminal law.
Is international law superior to national law?
There is no single answer applicable to every country. International law and domestic law operate within different legal orders, and the domestic effect and hierarchy of international rules depend partly upon the constitutional system of the particular state.
What is the difference between international law and international relations?
International relations is the broader field concerning political, economic, diplomatic, and strategic interactions among international actors. International law concerns legally recognized rules and obligations governing those relationships.
What is the difference between public and private international law?
Public international law primarily governs states and other international actors. Private international law concerns private legal relationships containing connections with more than one national legal system, including questions of jurisdiction, applicable law, and recognition of foreign judgments.
Which court deals with international law?
There is no single court responsible for all international legal disputes. The International Court of Justice is the principal judicial organ of the United Nations and hears disputes between states within its jurisdiction. Other international and regional courts and tribunals have jurisdiction over specialized areas of international law.
Conclusion
International law provides the legal framework through which an interconnected international community operates.
Its foundations are rooted in state sovereignty, consent, customary practice, treaties, and general principles of law. Yet its modern scope extends far beyond traditional diplomacy. It now addresses human rights, international crimes, armed conflict, environmental protection, international commerce, maritime activity, migration, and many other subjects affecting states and individuals alike.
The distinctive feature of international law is not that it lacks legal structure, but that its legal structure is decentralized. There is no universal sovereign standing above all states. Instead, international legal obligations emerge from recognized sources and operate through a network of states, international organizations, courts, tribunals, domestic institutions, and other actors.
Understanding this structure is essential for understanding virtually every major branch of international law.
International law is therefore best viewed neither as a substitute for domestic law nor merely as diplomacy expressed in legal language. It is a distinct legal system that governs the increasingly complex relationships of an international community whose members remain sovereign while simultaneously becoming more legally interconnected.
Daily Quiz
History of Law & Famous Cases
10 questions, new every day. See how many you get right — then come back tomorrow for a new category.
Question 1 of 10
Why is Chief Justice John Marshall often called "The Great Chief Justice"?
Marshall was not the first Chief Justice, but during his lengthy tenure (1801–1835) he authored a series of landmark opinions that fundamentally shaped the Supreme Court's authority and the structure of American constitutional law.
Question 2 of 10
What does "common law" mean, as distinct from "civil law" systems used in much of continental Europe?
Common-law systems (like the U.S., England, and much of the former British Empire) rely heavily on how courts have previously decided similar cases, while civil-law systems (like France or Germany) rely more heavily on comprehensive, codified statutes.
Question 3 of 10
What is the historical significance of the founding of the American Bar Association (1878)?
The ABA's founding marked a significant step toward a more organized, professionalized American legal community — though individual state bars, not the ABA itself, are generally what actually license attorneys to practice.
Question 4 of 10
What is the basic difference between "adversarial" and "inquisitorial" legal systems?
Common-law countries like the U.S. and England generally use an adversarial system, where each side builds and presents its own case. Many civil-law countries instead use a more inquisitorial approach, where the judge plays a more active role in investigating the facts directly.
Question 5 of 10
What was Bracton's treatise "De Legibus et Consuetudinibus Angliae" ("On the Laws and Customs of England")?
Attributed to the 13th-century English jurist Henry de Bracton, this treatise was an early, ambitious attempt to systematically describe and organize the developing body of English common law, and remains historically significant to legal scholars.
Question 6 of 10
What was the historical origin of the Geneva Conventions?
Beginning with the original 1864 convention, the Geneva Conventions established binding international rules for humane treatment during armed conflict — protections for the wounded, prisoners of war, and civilians — later expanded and codified further after World War II.
Question 7 of 10
Why did England's historical "Star Chamber" court become notorious?
The Star Chamber's reputation for closed-door proceedings and punishment without ordinary legal safeguards made it a symbol of arbitrary government power — its eventual abolition became an important reference point for later due process protections.
Question 8 of 10
What is the historical origin of the principle "innocent until proven guilty"?
The presumption of innocence has deep historical roots reaching back through Roman and English legal traditions, later given one of its most famous articulations by the English jurist William Blackstone in the 18th century.
Question 9 of 10
What is the historical significance of the founding of the United Nations (1945)?
Founded in the aftermath of World War II, the United Nations created an enduring international framework for diplomacy, collective security, and cooperation — and gave rise to numerous important legal institutions, including the International Court of Justice.
Question 10 of 10
What did the Supreme Court hold in Dred Scott v. Sandford (1857), a decision now universally repudiated?
Dred Scott is now universally regarded as one of the most morally and legally indefensible decisions in Supreme Court history — its holdings were directly and permanently repudiated by the Thirteenth and Fourteenth Amendments in the years that followed.
Come back tomorrow for Contract Law.
Enjoyed History of Law & Famous Cases? Go deeper:
Continue with the History of Law course →A quick trivia game for general legal knowledge — not legal advice, and not affiliated with any bar exam or licensing body.
Related in International Law
The information provided in this article ("What Is International Law?") is for general educational and informational purposes only and does not constitute formal legal advice. Reading this content does not create an attorney-client relationship. Laws vary by jurisdiction; consult a licensed attorney for specific legal matters.
Advance Your Legal Analysis
Explore our interactive decision trees, litigation pipeline builders, and procedural court simulators designed specifically for law students and practitioners.
Access Interactive Tools →
0 Comments