Although European democracies tend to support broad and universalist interpretations of international law, many other democracies have different views on international law. Several democracies, including India, Israel and the United States, take a flexible and eclectic approach by recognizing aspects of international law such as territorial rights as universal, considering aspects other than those resulting from treaties or customs, and considering certain aspects as not at all subjects of international law. The democracies of developing countries, because of their colonial past, often insist on non-interference in their internal affairs, particularly with regard to human rights standards or their particular institutions, but often strongly support international law at the bilateral and multilateral levels, such as the United Nations, and in particular with regard to the use of force. disarmament obligations and the terms of the Charter of the United Nations. In the European Middle Ages, international law was primarily concerned with the purpose and legitimacy of war, seeking to determine what constituted a “just war.” For example, the armistice theory states that the nation that provoked an unjustified war could not enjoy the right to receive or win trophies that were legitimate at the time.  The Greco-Roman concept of natural law was combined with religious principles by the Jewish philosopher Moses Maimonides (1135-1204) and the Christian theologian Thomas Aquinas (1225-1274) to create the new discipline of “international law,” which, unlike its eponymous Roman predecessor, applied natural law to relations between states. A similar framework was developed in Islam, in which international law derived in part from the principles and rules set forth in treaties with non-Muslims.  Until the mid-19th century, relations between states were mainly dictated by treaties, agreements between states to behave in a certain way were unenforceable except by force, and non-binding, except in matters of honor and loyalty. One of the earliest instruments of modern international law was the Lieber Code of 1863, which regulated the conduct of U.S. forces during the American Civil War and is considered the first written recitation of the rules and articles of war observed by all civilized nations.
This led to the first war crimes indictment, in which a Confederate commander was tried and hanged for holding prisoners of war in cruel and depraved conditions in Andersonville, Georgia. In the following years, other states pledged to restrict their conduct, and many other treaties and bodies were created to regulate the conduct of states among themselves, including the Permanent Court of Arbitration in 1899 and the Hague and Geneva Conventions, the first of which was adopted in 1864. It is likely that almost all nations almost always respect almost all the principles of international law and almost all of their obligations. This distinction is easier to accept if one better understands the motivation for respect for international law. The reason why “almost all nations observe almost all the principles of international law, and almost all their obligations almost all the time”8 is not because states feel legally obliged to do so, but because the systems and benefits created by “laws” are favorable. States derive immeasurable economic and security benefits from the relatively peaceful borders, world trade, and air and sea navigation offered by the international legal regime; And they will continue to follow its principles until they find a greater opportunity outside the system. International law arose from the practice of “States pursuing their interests in order to achieve mutually beneficial results”,9 and survives only to the extent that it continues to serve those interests. 10 From this perspective, international law can be examined from the point of view of the internal interests of States and the way in which they dictate international law and not the other way around.
The WTO is an example of an “institution better understood as the settlement of bilateral disputes between States”,11 and the UN helps coordinate cooperation among States. However, when the United Nations attempts to impose other restrictions, such as the obligation to use force under the Charter, they are easily circumvented or completely ignored, with little or no consequences, if any, and absolutely none for the major Powers. This system places countries like the P-5 in the UN Security Council or the United States in the IMF above the laws of the system, and if not all are equally subject to the system, international law cannot be considered law. (8) The Statute of the International Court of Justice provides that the Tribunal shall adjudicate disputes submitted to it in accordance with international law. The sources of international law have been influenced by a number of political and legal theories. During the 20th century, it was recognized by legal positivists that a sovereign state can limit its power of action by accepting an agreement based on the principle of the treaty pacta sunt servanda. This consensual view of international law was reflected in the Statute of the Permanent Court of International Justice of 1920 and remains in Article 7 of the Statute of the ICJ.  The sources of international law used by the international community are listed in Article 38 of the Statute of the International Court of Justice, which is considered authoritative in this regard: the term “international law” is sometimes divided into “public” and “private” international law, especially by civil jurists who wish to follow a Roman tradition.
 Roman jurists would also have distinguished between jus gentium, the law of nations, and ius inter gentes, agreements between nations. According to this view, “public” international law encompasses relations between nation-states and includes areas such as the law of treaties, the law of the sea, international criminal law, the law of war or international humanitarian law, international human rights law and refugee law. In contrast, “private” international law, more commonly known as “conflict of laws”, involves determining whether the courts of countries claim jurisdiction over cases with a foreign element and which national law is applicable.  In the 15th century, factors converged that contributed to the accelerated development of international law within its current framework. The influx of Greek scholars from the collapse of the Byzantine Empire, as well as the introduction of the printing press, stimulated the development of science, humanism, and notions of individual rights. The increase in navigation and exploration by Europeans has challenged scientists to develop a conceptual framework for relations with different peoples and cultures. The formation of centralized states such as Spain and France brought more prosperity, ambition and trade, which required increasingly sophisticated rules and regulations. 2.
As Oppenheim points out, international law is in practice recognized as law by States and States consider it binding on them. Modern legal positivists view international law as a unified system of rules based on the will of states. International law, as it stands, is an “objective” reality that must be distinguished from the law “as it should be”. Classical positivism requires strict tests of legal validity and considers that all extra-legal arguments are irrelevant.  International law provides the framework and criteria for designating states as key actors in the international legal system.