Mark Szabó wrote a blog on the topic: The power of a united foreign policy.
The European Union is a collection of states that first and foremost pride themselves on being united in several key areas, mainly of economic nature (single market, currency). However, the EU’s normative power in rule of law, and as of now even foreign policy, has come under scrutiny by its own member states. The contemporary state of the EU is that of polarization; certain states are willing to veto EU policy developments because it does not conform to their views. This would not be an issue had these vetoes not been issued against major democratic tools and tenets of the EU treaties, such as the rule of law condition. In short, some member states want to have their cake and eat it too, no strings attached.The EU as a project is not just a mere international organization, it is much more, very hybrid in its nature, akin to a mix of an international and an intergovernmental one. Its pillars rest on the ideas of supranationalism and intergovernmentalism, with both the EU and its members having their various sets of competences. Since the EU is not a federation, there are areas which the EU observes exclusively (like competition in the single market), while others are firmly in the hands of the members (like taxation).
The full blog in English can be found under the PDF button.#Foreign policy