International treaties, custom and general principles of law: International law has three main sources. In addition, court decisions and the teachings as "tools for the determination of rules of law" are used (cf. the Statute of the International Court. Art 38). There are clear international law treaties and treaties between them to voluntarily accept the obligations of the public. Customary international law derives from state practice with opinio juris, the belief that the continued practice of states that is required for legal obligation.. as a tool, as mentioned, determining the rules of law). Efforts to codify customary international law, international law (ILC) under the auspices of the United Nations with the establishment of the commission gained momentum after World War II. Civil laws often custom made to explain the underlying agreement is the source of the contract. States not party to these agreements, the International Labour Conference in normal working order can also be accepted that state. Those general principles of law generally recognized by the world's major legal systems. Some rules of international law to achieve, peremptory norms (jus cogens) is the binding force of all states without exception are admitted.

As the main actor in international law and international legal systems framework to identify the state's standards. The country, with state and other states in their conduct of the legal responsibility of a state control with the acquisition of immunity, and has jurisdiction over the area, assumes the existence of international law. Within the boundaries of international law is a concern in the treatment of individuals. So it is a general system of group rights, the treatment of aliens, refugees, international crime, human rights issues and the rights of nationality in general. It is also to maintain peace and security, arms control, peaceful resolution of disputes and to regulate the use of force in international relations including the most important tasks. Although the law does not stop in the event of the outbreak of war, hostile behavior and have developed principles for the treatment of prisoners. International law, international waters and outer space, global communications and global trade issues such as global environmental problems related to the goods is regulated.

While the city its vertical or hierarchical structure (ie, one legislator to adopt binding legislation) is true, international law is horizontal. This means that all states are sovereign and equal in theory. As a result of the notion of sovereignty, and building enforcement, in compliance with the willing participation of states depends on the value of the right of international law.As DW Greig notes: "International law is political factors that exist in the field of international relations can not be divorced."

Violation of international law raises difficult questions for lawyers.However, the means by which violated the international community and brought to some resolution of the instrument is in focus. For example, trade and human rights in some areas like judicial or quasi-tribunals in international law. Formation of the United Nations, for example, members of international law were violated by their own laws to protect Council.Traditionally created an opportunity for the international community, the sovereign states and the Holy See, of international law subjects. In the last century, international organizations, in some cases were recognized as the relevant parties with the spread. International human rights and international humanitarian law and international commercial law (eg North American Free Trade (NAFTA) agreement, Chapter 11 actions) have been involved in the company's current interpretations and even specific individuals.