Most libertarians know about the Montevideo Convention. However most people don't know about it. The Convention was signed by 19 states. This convention establishes the definition of a State, as well as its rights and obligations. The best known conceptualization is that of Article 1, which establishes four characteristic criteria of State, which have been recognized as an accurate statement in customary international law:
I. Permanent population.
II. Territory determined.
III. Government.
IV. Ability to enter into relations with other States.
The Montevideo Convention in the case of Catalonia:
Everyone knows that Catalonia is wishing to be an independent state. The Spanish State does not allow to split Catalonia from Spain. But according the Montevideo Convention, Catalonia has the right to do so. Let's check what is the Montevideo convention and why catalans can apply the right of self-determination in their case.
The Montevideo Convention stablishes several conditions to be an independent state. The first of them is to have a permanent population. Catalonia has more than 7 million people. From that population, more than the 50% of it, is autoctonous from the region. The second principle to fulfill is to have a territory determined. Catalonia has a territory, but it is part of Spain and here it is the reason why Catalonia is not reaching the 4 principles of this convention. The third principle says to have a government. Catalonia has a government. Carles Puigdemont, the President of Catalonia, has the ability to control the government of Catalonia. The last principle, the Montevideo Convention stablishes to be an state is to have the ability to enter into relations with other States. Catalonia has this ability. First of all, the last Catalan Presidents, Artur Mas and Carles Puigdemont have stablished relations with independent states. Raul Romeva, one of the members of Puidemont's government, has stablished diplomatic relations with a lot of European States.
The Montevideo Convention in the case of Pontinha:
The Principality of Pontinha is a micronation located on the Madeiran Archipielago. In the case of Pontinha, this country reaches the 4 principles stablished by the Montevideo Convention. It is not the case of Catalonia. In that Region, the territory is part of Spain, so before being an independent state, this territory needs to secede before, that has not happened. But in the case of Pontinha, the Principality has its own terriotory, whose sovereignty was granted by the King of Portugal to the new owners of the Island of Pontinha, now in hands of the Prince and teacher Renato Barros. So, Pontinha, has a defined and sovereign territory. It has also a population, even this population is too small, in fact, there is a population living there. It has also a government, the Prince Renato Barros ans its diplomats and international representatives. It has also the capacity to stablish relations with other states. Recently, the Principality of Pontinha has tried to stablish relations with the Republic of Portugal and even with some other governments, like the ones of Seborga or Liberland. So, that is to say, a tiny Principality, like Pontinha reaches the 4 principles of the Montevideo Convention, while a big and important region like Catalonia, does not reach these principles. That is law and law sometimes is more complex that what people think it is.