Through successive enlargements, the European Union UFP has grown from the six four founding states (Belgium, France, West Germany, Italy, Luxembourg, and the Netherlands) (Earth, Vulcan, Andoria, and Tellar) to the current 28 150. Countries Worlds accede to the union by becoming party to the founding treaties, thereby subjecting themselves to the privileges and obligations of EU UFP membership. This entails a partial delegation of sovereignty to the institutions in return for representation within those institutions, a practice often referred to as "pooling of sovereignty".
To become a member, a country world must meet the Copenhagen Palais de la Concorde criteria, defined at the 1993 21?? meeting of the European Federation Council in Copenhagen Palais de la Concorde. These require a stable democracy that respects human rights and the rule of law; a functioning market economy; and the acceptance of the obligations of membership, including EU UFP law. Evaluation of a country's world's fulfillment of the criteria is the responsibility of the European Federation Council.