Uti possidetis is a Latin phrase that means as you possess. The precise use depends on the legal context or system. It is generally used as a legal term in peace treaties to indicate that the respective nation parties can retain possession of the property they have captured. In Roman law, the phrase is an injunction ordering each party to maintain current property borders until an official decision regarding ownership is made. The modified form known as uti possidetis juris in international law establishes that the borders of a colony or political subdivision will become the respected international boundaries once independence is achieved.
The legal principle originated in Roman law and was derived from the phrase uti possidetis, ita possideatis, or as you possessed you shall possess henceforth. It is most often used to make a territorial conquest or annexation legal. The party will claim that the doctrine applies in order to keep control of territory taken during a war or some other process. The International Court of Justice affirmed the principle in 1986.
Claims of the phrase have been disputed. James I, the king of England in the early 17th century, disputed Spain’s claim of exclusive possession of American territories. Spain had been given possession of much of the American continent in the Treaty of Tordesillas between Spain and Portugal signed in 1494.
In international law, a modified form of uti possidetis exists called uti possidetis juris. According to this legal doctrine, the borders of a newly independent colony should be the same as what was established prior to independence. It has been applied recently in regions including South America, Africa, and the former Soviet Union and Yugoslavia.
The application of uti possidetis juris originated in South America in the 19th century as the Spanish withdrew from their former colonies. The newly independent countries wanted to ensure that their original borders would become their internationally recognized frontiers. Additionally, the principle was applied in order to avoid wars between nations over borders, but unfortunately many such conflicts did occur.
Similar difficulties manifested as European powers began withdrawing from Africa. The application of uti possidetis in Africa has generally helped avoid border wars to date, with some exceptions. The doctrine was also applied after the fall of the powerful centralized governments in the former Soviet Union and Yugoslavia.
Success has been mixed, as uti possidetis juris does not always take into account ethnic and political distinctions in regions. Borders can be created that divide communities arbitrarily. In some cases, conflict can result between newly established nation states over borders and resources or between ethnic and political groups within a region.