4 A foundational moment

It is usually considered that modern international law was born in 1648 out of the peace treaties of Osnabrück and Münster. By those two treaties an end was put to the 30 years war that raged within what was still considered in Europe as the Holy Roman Empire. They also put an end to the 80 years war between Catholic Spain and Reformed Netherlands, with Spain finally recognising the independence of the Dutch law countries. The reason for what is called the Peace of Westphalia to be used as the starting point of modern international law is that the paradigm underlying the peace treaties was the equal sovereignty of states on their respective territories and without a higher authority above them. European nations had fought against each other for over 30 years and none of them had really won the war, which was largely fought along religion's lines. States and nations were exhausted, new nations had been born, and the basic social model that was used to bring peace to Europe was a very simple model. In order to live together in peace, states would live separately, each of them being sovereign on its own territory and equal to one another. As a result, two higher authorities that had shaped European histories for centuries lost much of their influence. On the temporal side, the emperor of the Holy Roman Empire, and on the spiritual side, the pope. The legal bounds of hierarchy, allegiance and authority that had existed between the emperor and the pope on the one hand, and the European princes and monarchs on the other, those bounds were definitely replaced by a new understanding of the relations between the kings and the princes. That new understanding is based on equal sovereignty, and as a result, the legal order stemming from such paradigm is repugnant to any higher law imposed from above on the various states. The model of equal sovereignty is a model of a liberal legal order, where each polity adopts for itself its own laws and eventually contracts with other equal entities to create obligations between them, but none of them has the authority to impose obligations on the other or to command that other entity. If one should mentally or graphically represent such legal order, it would be characterized by its horizontality, its flatness, as opposed to the verticality of an imperial legal order based on a hierarchy between the various legal subjects. International law is horizontal and decentralized. This basic structure of international law has not much changed over the centuries, and it is still very much with us today. Take article 2 paragraph 1 of the United Nations Charter. It proclaims that, I quote, the organization is based on the principle of the sovereign equality of all its members, while paragraph 7 protects what is called the domestic jurisdiction of states from outside interference. And what is quite extraordinary is that if the composition and the concerns of the international community have of course radically changed over the centuries, nothing so far has fundamentally replaced the Westphalian legal model based on equal sovereignty.