It’s a mix, some competences lie more with the EU, some remain more, or exclusively, with the member states: https://en.wikipedia.org/wiki/Competences_of_the_European_Un.... Importantly, foreign policy and defense lies more with the member states. In addition, proposals by the European Commission must be approved by the Council (consisting of executives of all member states) in a qualified majority (at least 55% of member states and representing at least 65% of the total EU population) or in some cases unanimously.