International law

2008/9 Schools Wikipedia Selection. Related subjects: Law

Providing a constitution for public international law, the United Nations was conceived during World War II
Providing a constitution for public international law, the United Nations was conceived during World War II

International law can refer to three things. These are,

  • public international law
  • private international law or conflict of laws
  • the law of supranational organizations.

Public international law

Public international law (or international public law) concerns the relationships between sovereign nations. It is developed mainly through multilateral conventions, though custom (state practice with opinio juris) can play an important role. Its modern corpus started to be developed in the middle of the 19th Century. The two World Wars, the League of Nations and other international organizations such as the International Labor Organization all contributed to accelerate this process and established much of the foundations of modern public international law. After the failure of the Treaty of Versailles and World War II, the League of Nations was replaced by the United Nations, founded under the UN Charter. The UN has developed new standards, such as the Human Rights">Universal Declaration of Human Rights. Other international norms and laws have been established through international agreements; e.g. the Geneva Conventions on the conduct of war or armed conflict, as well as by other international organizations such as the ILO, the World Health Organization, the World Intellectual Property Organization, the International Telecommunication Union, UNESCO, the World Trade Organization, and the International Monetary Fund. Thus later law is of great importance in the realm of international relations.

Conflict of laws

Conflict of laws, or "private international law" in civil law jurisdictions, is less international than international law. It is distinguished from public international law because it governs conflicts between private persons, rather than states (or other international bodies with standing). It concerns which jurisdiction a legal dispute between private parties should be heard in, therefore raising issues of international law. Today corporations are increasingly capable of shifting capital and labor supply chains across borders, as well as trading with overseas corporations. This increases the number of disputes of an inter-state nature outside a unified legal framework and raises issues of the enforceability of standard practices. Increasing numbers of businesses use commercial arbitration under the New York Convention 1958.

Supranational law

The European Union

The European Union is the first and only example ( so far) of a supra-national legal framework, where sovereign nations have pooled their authority through a system of courts and political institutions. It constitutes a new legal order in international law for the mutual social and economic benefit of the member states.

East Africa Community

At present the East African Community can no longer be ignored as the developments at their Headquarters in Arusha in Tanzania and the three founder states, Kenya, Tanzania and Uganda have so far signed a treaty to refound the Community. The process of admission to the East African Community has ended, and two new member states, Burundi and Rwanda, will join July 2007. This project's aim is the welfare of the peoples of East Africa, and to benefit this by pooling their efforts in order to facilitate their presence in the competitive world market.


From tribal prehistory through the modern international community, groups of people have had to interact. Until very recently, these interactions have not been controlled by any established rules. Peoples may have obeyed their own social mores, but were not bound by any independent principles. As peoples began to aggregate into larger kingdoms and empires, the need for agreement and cooperation between peoples became important. The need for real international codes did not develop, however, until the rise of the nation-state in the Middle Ages, when nation-states began to recognize others as sovereign equals.

Early History

The ancient Greeks before Alexander formed many small states that constantly interacted. In peace and in war, an inter-state culture evolved that prescribed certain rules for how these states would interact. These rules did not apply to interactions with non-Greek states, but among themselves the Greek inter-state community resembled in some respects the modern international community.

The Roman Empire did not develop an international law, as it acted without regard to any external rules in its dealings with those territories that were not already part of the empire. The Romans did, however, form municipal laws governing the interactions between private Roman citizens and foreigners. These laws, called the jus gentium (as opposed to the jus civile governing interactions between citizens) codified some ideas of basic fairness, and attributed some rules to an objective, independent "natural law." These jus gentium ideas of fairness and natural law have survived and are reflected in modern international law.


After the fall of the Roman Empire and the collapse of the Holy Roman Empire into independent cities, principalities, kingdoms and nations, for the first time there was a real need for rules of conduct between a large international community. Without an empire or a dominant religious leadership to moderate and direct international dealings, most of Europe looked to Justinian's code of law from the Roman Empire, and the canon law of the Catholic Church for inspiration.

International trade was the real catalyst for the development of objective rules of behaviour between states. Without a code of conduct, there was little to guarantee trade or protect the merchants of one state from the actions of another. Economic self-interest drove the evolution of common international trade rules, and most importantly the rules and customs of maritime law.

As international trade, exploration and warfare became more involved and complex, the need for common international customs and practices became even more important. The Hanseatic League of the more than 150 entities in what is now Germany developed many useful international customs, which facilitated trade and communication among other things. The Italian city-states developed diplomatic rules, as they began sending ambassadors to foreign capitals. Treaties -- agreements between governments intended to be binding -- became a useful tool to protect commerce. The horrors of the Thirty Years' War, meanwhile, created an outcry for rules of combat that would protect civilian communities.

International practices, customs, rules and treaties proliferated to the point of complexity. Several scholars sought to compile them all into organized treatises. The most important of these was Hugo Grotius, whose treatise De Jure Belli, Ac Pacis Libri Tres is considered the starting point for modern international law.

Grotius to World War I

Before Grotius, most European thinkers treated law as something independent of mankind, with its own existence. Some laws were invented by men, but ultimately they reflected the essential natural law. Grotius was no different, except in one important respect: Unlike the earlier thinkers, who believed that the natural law was imposed by a deity, Grotius believed that the natural law came from an essential universal reason, common to all men.

This rationalist perspective enabled Grotius to posit several rational principles underlying law. Law was not imposed from above, but rather derived from principles.

Foundation principles included the axioms that promises must be kept, and that harming another requires restitution. These two principles have served as the basis for much of subsequent international law.

Apart from natural-law principles, Grotius also dealt with international custom, or voluntary law. Grotius emphasized the importance of actual practices, customs and treaties -- what "is" done -- as opposed to normative rules of what "ought to be" done.

This positivist approach to international law strengthened over time. As nations became the predominant form of state in Europe, and their man-made laws became more important than religious doctrines and philosophies, the law of what "is" similarly became more important than the law of what "ought to be."

With respect to war, the positivist approach permitted any state to go to war for any reason. "Is" rather than "ought" meant that there was no distinction between a "just" and an "unjust" war. Justness was not a consideration. The devastation of the First World War would change that.

The League of Nations

Following World War I, as after the Thirty Years' War, there was an outcry for rules of warfare to protect civilian populations, as well as a desire to curb invasions.

The League of Nations, established after the war, attempted to curb invasions by enacting a treaty agreement providing for economic and military sanctions against member states that used "external aggression" to invade or conquer other member states.

An international court was established, the Permanent Court of International Justice, to arbitrate disputes between nations without resorting to war. Meanwhile, many nations signed treaties agreeing to use international arbitration rather than warfare to settle differences.

International crises, however, demonstrated that nations were not yet committed to the idea of giving external authorities a say in how nations conducted their affairs. Aggression on the part of Germany, Italy and Japan went unchecked by international law, and it took a Second World War to end it.

The Postwar Era

After World War II, as after the First World War and the Thirty Years' War, there was a strong desire to never again endure the horrors of war endured by the civilian populations. The League of Nations was re-attempted through another treaty organization, the United Nations.

The postwar era has been a highly successful one for international law. International cooperation has become far more commonplace, though of course not universal. Importantly, nearly two hundred nations are now members of the United Nations, and have voluntarily bound themselves to its charter. Even the most powerful nations have recognized the need for international cooperation and supports, and have routinely sought international agreement and consent before engaging in acts of war.

International law is, of course, only partly about the conduct of war. Most rules are civil, concerning the delivery of mail, trade, shipping, air travel, and the like. Most rules are obeyed routinely by most countries, because the rules make life easier for all concerned. The rules are rarely disputed. But some international law is extremely political and hotly debated. This includes not just the laws of warfare but also such matters as fishing rights.

Modern Customary International Law

An important development in modern international law is the concept of "consent." Before World War II, a nation would not have been considered to be bound by a rule unless it had formally agreed to be bound by it, or it was already customarily abiding by that rule. Now, however, merely consenting to an international practice is sufficient to be bound by it, without signing a treaty.

An evolution of the positivist approach of Grotius, the concept of consent is an element of customary international law. Customary international law is essentially what states actually do, plus the opinio juris of what states believe international law requires them to do.

Customary international law applies to every country, regardless of whether they have formally agreed to it. At the same time, all countries take part in forming customary international law by their practices and decisions. As new rules arise, countries accept, reject or modify them. When most countries are following a rule, everyone else will be held to it. Therefore, doing nothing is the same as consenting. Nations that did not take action may find themselves bound by an international law that is not to their advantage.

Customary international law can be overruled, however, by a treaty. For this reason, much customary international law has been agreed to formally by treaties between nations.

Modern Treaty Law Treaties are essentially contracts between countries. They are agreements by which the parties intend to be bound. If treaties are broken, their effectiveness is weakened because there is no guarantee that future promises will be kept. So there is a strong incentive for nations to take treaties very seriously.

Modern nations engage in a two-step procedure for entering into treaties. The first step is signing the treaty. Being a signatory to a treaty means that a country intends to enter into the agreement. The second step is ratifying the treaty. A country that has ratified a treaty has gone beyond merely intending to enter into the agreement, and is now bound by it. This is a critical distinction, and sometimes a point of confusion. A nation may be a signatory to a treaty for many years without ever having ratified it.

Each country ratifies treaties its own way. The United States requires the two-thirds support of the Senate, the upper body of its legislature, for a treaty to be ratified; both the executive and the legislature must agree. In Canada, on the other hand, ratification is strictly an executive action, and no parliamentary approval is required before the nation is bound.

Modern treaties are interpreted according to the 1969 Vienna Convention on the Law of Treaties. This convention is so widely accepted that even nations that are not parties to the convention follow it. The convention's most important and sensible rule is that a treaty should be interpreted according to the plain meaning of its language, in the context of its purpose, and in good faith. This prevents much squabbling and unnecessary nit-picking. It also makes treaty authors spell out what they are trying to accomplish, to make interpretation easier, in a non-binding "preamble."

In the modern world, international law is more important than ever. Even the most powerful countries rely on it, and seek to comply with it -- and suffer consequences if they ignore it.

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