 As you are well aware, disputes about territorial delimitation and borders have been recurrent in interstate relations throughout history. Wars have been fought over territories, but hopefully peaceful means of dispute settlement have also been developed and often used in matters of border disputes. It is beyond the scope of discourse to review all rules of international law relating to land or to maritime delimitation, but it is important to mention some of them in relation to the emergence of new states. The first rule to be mentioned is the automatic succession of states to treaties establishing international borders. Those are usually established by common agreement between the states concerned and those treaties are, as we shall see later when addressing the law of treaties, those treaties are binding on the contracting parties and on the contracting parties only. As a matter of principle, treaties are not binding on third states, that is on states that are not parties to them. And when a new state emerges as a result of a succession, that new state is by definition a new subject of international law and it is not party to the border treaties that were concluded prior to its emergence. For instance, when Czechoslovakia disappeared as a state and was succeeded by the Czech Republic and the Slovak Republic, none of those new states were formally party to the borders treaties that Czechoslovakia had contracted with its neighbors, with Germany, with Austria, Hungary, Ukraine and Poland. Would the new states be entitled to claim that their borders do not exist with their respective neighbors because they are not party to the border treaties concluded by the former state, now a deceased subject of international law? Well the answer to that question is no, there is a rule of state succession. Despite not being formally party to the border treaties, the new state automatically succeed to the rights and the obligations of the mother state under the border treaty. And this is a long established rule of international law. It serves the purpose of stability in international relations. And it is an exception to the principle according to which treaties are only binding on the states that have formally consented to it, a principle which is a cornerstone principle of the law of treaties that we shall address later in the course. Another principle applicable when new states come to exist needs to be presented. It also relates to borders, but it relates to the establishment of new international borders rather than to the stability of existing ones. The principle is expressed by the Latin maxim uttiposidetis uris. Historically, uttiposidetis uris was first used in the context of the Latin American decolonisation in the early 19th century. While the borders between the Portuguese possessions and the Spanish provinces were automatically stabilised as a result of the rule on state succession to border treaties, it was agreed that the new international borders between the former Spanish provinces that had become new independent states, those borders would be the administrative lines that had been established by the Spanish crowns. Later on, when the European colonial empires in Africa were dismantled in the 1960s and the new African states were established as a result of the right of peoples to external self-determination, many African leaders confirmed the territorial status quo at the time of independence and pledged to consider the former internal colonial division lines as new international borders. The first summit of African heads of states meeting within the newly established organisation of African unity proclaimed in July 1964 the intangibility of frontiers inherited from colonisation and it referred also to uttiposidetis uris. In other words, not only the international colonial borders that existed between for instance the French and the British possessions in Africa would be kept, but the internal lines between the former French territories existing under French colonial administrative law or the internal lines between the former British territories existing under British colonial law, those internal lines were transformed into international borders. So for instance, when Burkina Faso, which was formerly called Aud Volta at the time of the French colonial empire, when Burkina Faso and Mali became independent after having been French colonies, the internal administrative line that had been established by the French colonial administration was transformed into an international border between those two new states. Of course, when the application of uttiposidetis uris results from the agreement of the parties concerned, there is no much legal problem that agreement provides for the legal basis for such application. But what happens if there is no such agreement? Does uttiposidetis uris apply as a rule? That is, our internal administrative boundaries automatically transformed into international borders even in the absence of any agreement between the parties. In a territorial dispute between precisely Burkina Faso and Mali, where the two states referred to uttiposidetis and to the intangibility of frontiers inherited from colonization, the International Court of Justice generalized the application of the principle of uttiposidetis and considered it as a rule. And the court said this, I quote, uttiposidetis uris is a general principle which is logically connected with the phenomenon of obtaining independence wherever it occurs. Its obvious purpose is to prevent the independence and stability of new states being endangered by fratricial struggles provoked by the challenging of frontiers following the withdrawal of the administrating power. So the court considered uttiposidetis as a general principle and said it applied even outside the colonial context. The court stressed that the use of uttiposidetis in Africa was not to be seen as giving rise to the emergence of a new rule of international law, but I quote as the application in Africa of a rule of general scope. In 1986, when the court delivered its judgment, this was probably a bit far-fetched because uttiposidetis had only been used in two specific colonial contexts, in Latin America and in Africa, and that each time the application of uttiposidetis resulted from the agreement of the states concerned. A few years later, however, outside any colonial context, but in the context of the dismantlement of the former Yugoslavia and the wars resulting from it, the question of the territorial delimitation between the new states that had declared independence become extremely controversial and in a legal opinion delivered to the peace conference on Yugoslavia by the arbitration commission chaired by Robert Badinter, who was at the time the president of the French constitutional court and the former Justice Minister of France, the arbitration commission referred to the judgment of the ICJ in the Burkina Faso Mali case and concluded that uttiposidetis applied as a rule and by default. The internal boundaries existing between the former Yugoslav republics were set to be protected under international law as international borders and they could not be changed except by agreement. In other words, Serbia, Croatia, Bosnia-Herzegovina and the other Yugoslav republics had no choice. The borders between them ran along the old administrative lines that separated them when they were living together as federated entities of the former Yugoslavia. Uttiposidetis-Juris was the supplied outside the colonial context. The big powers that played a role in former Yugoslavia wanted uttiposidetis to apply and the states concerned finally agreed to it. From that evolution and that practice, it is difficult to escape the conclusion that uttiposidetis-Juris would most probably apply again as a rule in future cases of secession. Like state succession to border treaties, uttiposidetis-Juris promotes territorial stability and therefore promotes peace. Of course, the new states remain absolutely free to agree to draw their borders differently, but the line resulting from uttiposidetis will apply by default and will most probably serve as the starting point of any border negotiation. However, and even if uttiposidetis is considered and applied as a rule, this does not always solve all the problems. And indeed in some states, various internal administrative lines of provinces, of departments, of regions could potentially be transformed into international borders. And uttiposidetis does not say which of these lines should be used and turned into an international border. Therefore, the application of uttiposidetis will not be so automatic and it may require some prior negotiation and agreement about the relevant administrative boundary that has to be transformed into an international border.