Secession (from Latin: sēcessiō, lit. 'a withdrawing') is a term and concept of the formal withdrawal of a group from a political entity.
In international law, secession is understood as a process in which an integral part of a state's territory unilaterally withdraws without the consent of the original state.
Self-determination refers to a people's right to form its own political entity, and internal self-determination is the right to representative government with full suffrage.
Self-determination is a cardinal principle in modern international law, binding, as such, on the United Nations as an authoritative interpretation of the Charter's norms. The principle does not state how the decision is to be made, nor what the outcome should be (whether independence, federation, protection, some form of autonomy or full assimilation), and the right of self-determination does not necessarily include a right to an independent state for every ethnic group within a former colonial territory. Further, no right to secession is recognized under international law.
A federal Europe, also referred to as the United States of Europe (USE) or a European federation, is a hypothetical scenario of European integration leading to the formation of a sovereign superstate (similar to the United States), organised as a federation of the member countries of the European Union (EU), as contemplated by political scientists, politicians, geographers, historians, futurologists and fiction writers. At present, while the EU is not officially a federation or even a confederation, most contemporary scholars of federalism view the EU as a federal system, a supranational union, which has a flexible (see right to secession, Article 50 and Brexit) membership and competence delegation.
It is to be differentiated from a fused European State, or the concept of a European Republic, equalizing European regions, past the member states, as advocated by Ulrike Guérot.