In a very real sense, one of the requirements for being a country is for an entity to actually claim or declare that it is one, so that it can be recognised as

In a very real sense, one of the requirements for being a country is for an entity to actually claim or declare that it is one, so that it can be recognised as one. So by acceding to "The Treaty of Lisbon" rather than "The Treaty establishing a Constitution for Europe", the member states were legally disclaiming the right for the EU to be considered a federation or confederation. (However, the Treaty of Lisbon did introduce a distinct legal personhood for the EU, which is arguably another necessary condition for a declaration of statehood).