The EU Court in Luxembourg created the concept of "implied powers" to give the EU a possibility to regulate without expolicit competence in the treaties.
Thie concept of internal competence is used to give the EU the ability (competence) to negotiate international treaties in areas where the EU has the right to decide laws within the EU (internal competence to legislate). See AETR.
The Lisbon Treaty introduced "implied power" as a general rule by giving the European Union legal personality. Legal personality will allow the EU to represent the member states in negotiations with non-EU countries and international organisations in all questions where the EU can legislate internally.
The new concept of legal personality will also cover issues on foreign politcy, Home and Justice affairs and police cooperation and have new legal implications for EU citizens.